diff --git a/src/all/mangadex/build.gradle b/src/all/mangadex/build.gradle
index a10f7a7df..0dea04520 100644
--- a/src/all/mangadex/build.gradle
+++ b/src/all/mangadex/build.gradle
@@ -6,7 +6,7 @@ ext {
     extName = 'MangaDex'
     pkgNameSuffix = 'all.mangadex'
     extClass = '.MangaDexFactory'
-    extVersionCode = 167
+    extVersionCode = 168
     isNsfw = true
 }
 
diff --git a/src/all/mangadex/src/eu/kanade/tachiyomi/extension/all/mangadex/MDConstants.kt b/src/all/mangadex/src/eu/kanade/tachiyomi/extension/all/mangadex/MDConstants.kt
index 7bd954526..479b6fd4f 100644
--- a/src/all/mangadex/src/eu/kanade/tachiyomi/extension/all/mangadex/MDConstants.kt
+++ b/src/all/mangadex/src/eu/kanade/tachiyomi/extension/all/mangadex/MDConstants.kt
@@ -6,8 +6,10 @@ import java.util.TimeZone
 
 object MDConstants {
 
-    val uuidRegex =
-        Regex("[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}")
+    const val UUID_REGEX = "[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}"
+
+    val uuidRegex = UUID_REGEX.toRegex()
+    val onlyUuidRegex = "^$UUID_REGEX$".toRegex()
 
     const val mangaLimit = 20
     const val latestChapterLimit = 100
@@ -103,6 +105,11 @@ object MDConstants {
         return "${blockedUploaderPref}_$dexLang"
     }
 
+    private const val hasSanitizedUuidsPref = "hasSanitizedUuids"
+    fun getHasSanitizedUuidsPrefKey(dexLang: String): String {
+        return "${hasSanitizedUuidsPref}_$dexLang"
+    }
+
     const val tagGroupContent = "content"
     const val tagGroupFormat = "format"
     const val tagGroupGenre = "genre"
diff --git a/src/all/mangadex/src/eu/kanade/tachiyomi/extension/all/mangadex/MangaDex.kt b/src/all/mangadex/src/eu/kanade/tachiyomi/extension/all/mangadex/MangaDex.kt
index 11841693d..5f8ca93aa 100644
--- a/src/all/mangadex/src/eu/kanade/tachiyomi/extension/all/mangadex/MangaDex.kt
+++ b/src/all/mangadex/src/eu/kanade/tachiyomi/extension/all/mangadex/MangaDex.kt
@@ -64,6 +64,10 @@ abstract class MangaDex(final override val lang: String, private val dexLang: St
         .addInterceptor(MdAtHomeReportInterceptor(network.client, headers))
         .build()
 
+    init {
+        preferences.sanitizeExistingUuidPrefs()
+    }
+
     // POPULAR Manga Section
 
     override fun popularMangaRequest(page: Int): Request {
@@ -745,15 +749,11 @@ abstract class MangaDex(final override val lang: String, private val dexLang: St
             title = helper.intl.blockGroupByUuid
             summary = helper.intl.blockGroupByUuidSummary
 
-            setOnPreferenceChangeListener { _, newValue ->
-                val groupsBlocked = newValue.toString()
-                    .split(",")
-                    .map { it.trim() }
-                    .filter { helper.containsUuid(it) }
-                    .joinToString(", ")
+            setOnBindEditTextListener(helper::setupEditTextUuidValidator)
 
+            setOnPreferenceChangeListener { _, newValue ->
                 preferences.edit()
-                    .putString(MDConstants.getBlockedGroupsPrefKey(dexLang), groupsBlocked)
+                    .putString(MDConstants.getBlockedGroupsPrefKey(dexLang), newValue.toString())
                     .commit()
             }
         }
@@ -763,15 +763,11 @@ abstract class MangaDex(final override val lang: String, private val dexLang: St
             title = helper.intl.blockUploaderByUuid
             summary = helper.intl.blockUploaderByUuidSummary
 
-            setOnPreferenceChangeListener { _, newValue ->
-                val uploaderBlocked = newValue.toString()
-                    .split(",")
-                    .map { it.trim() }
-                    .filter { helper.containsUuid(it) }
-                    .joinToString(", ")
+            setOnBindEditTextListener(helper::setupEditTextUuidValidator)
 
+            setOnPreferenceChangeListener { _, newValue ->
                 preferences.edit()
-                    .putString(MDConstants.getBlockedUploaderPrefKey(dexLang), uploaderBlocked)
+                    .putString(MDConstants.getBlockedUploaderPrefKey(dexLang), newValue.toString())
                     .commit()
             }
         }
@@ -795,4 +791,28 @@ abstract class MangaDex(final override val lang: String, private val dexLang: St
     private inline fun <reified T> Response.parseAs(): T = use {
         helper.json.decodeFromString(body?.string().orEmpty())
     }
+
+    private fun SharedPreferences.sanitizeExistingUuidPrefs() {
+        if (getBoolean(MDConstants.getHasSanitizedUuidsPrefKey(dexLang), false)) {
+            return
+        }
+
+        val blockedGroups = getString(MDConstants.getBlockedGroupsPrefKey(dexLang), "")!!
+            .split(",")
+            .map(String::trim)
+            .filter(helper::isUuid)
+            .joinToString(", ")
+
+        val blockedUploaders = getString(MDConstants.getBlockedUploaderPrefKey(dexLang), "")!!
+            .split(",")
+            .map(String::trim)
+            .filter(helper::isUuid)
+            .joinToString(", ")
+
+        edit()
+            .putString(MDConstants.getBlockedGroupsPrefKey(dexLang), blockedGroups)
+            .putString(MDConstants.getBlockedUploaderPrefKey(dexLang), blockedUploaders)
+            .putBoolean(MDConstants.getHasSanitizedUuidsPrefKey(dexLang), true)
+            .apply()
+    }
 }
diff --git a/src/all/mangadex/src/eu/kanade/tachiyomi/extension/all/mangadex/MangaDexHelper.kt b/src/all/mangadex/src/eu/kanade/tachiyomi/extension/all/mangadex/MangaDexHelper.kt
index bfb91b06d..346b98961 100644
--- a/src/all/mangadex/src/eu/kanade/tachiyomi/extension/all/mangadex/MangaDexHelper.kt
+++ b/src/all/mangadex/src/eu/kanade/tachiyomi/extension/all/mangadex/MangaDexHelper.kt
@@ -1,6 +1,10 @@
 package eu.kanade.tachiyomi.extension.all.mangadex
 
+import android.text.Editable
+import android.text.TextWatcher
 import android.util.Log
+import android.widget.Button
+import android.widget.EditText
 import eu.kanade.tachiyomi.extension.all.mangadex.dto.AtHomeDto
 import eu.kanade.tachiyomi.extension.all.mangadex.dto.ChapterDataDto
 import eu.kanade.tachiyomi.extension.all.mangadex.dto.MangaAttributesDto
@@ -19,7 +23,6 @@ import okhttp3.HttpUrl.Companion.toHttpUrl
 import okhttp3.OkHttpClient
 import okhttp3.Request
 import org.jsoup.parser.Parser
-import uy.kohesive.injekt.api.get
 import java.util.Date
 import java.util.Locale
 import java.util.concurrent.TimeUnit
@@ -62,6 +65,11 @@ class MangaDexHelper(private val lang: String) {
      */
     fun containsUuid(url: String) = url.contains(MDConstants.uuidRegex)
 
+    /**
+     * Check if the string is a valid uuid
+     */
+    fun isUuid(text: String) = text.matches(MDConstants.onlyUuidRegex)
+
     /**
      * Get the manga offset pages are 1 based, so subtract 1
      */
@@ -394,4 +402,33 @@ class MangaDexHelper(private val lang: String) {
                 currentSlug
             }
         }
+
+    /**
+     * Adds a custom [TextWatcher] to the preference's [EditText] that show an
+     * error if the input value contains invalid UUIDs. If the validation fails,
+     * the Ok button is disabled to prevent the user from saving the value.
+     */
+    fun setupEditTextUuidValidator(editText: EditText) {
+        editText.addTextChangedListener(object : TextWatcher {
+
+            override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {}
+
+            override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {}
+
+            override fun afterTextChanged(editable: Editable?) {
+                requireNotNull(editable)
+
+                val text = editable.toString()
+
+                val isValid = text.isBlank() || text
+                    .split(",")
+                    .map(String::trim)
+                    .all(::isUuid)
+
+                editText.error = if (!isValid) intl.invalidUuids else null
+                editText.rootView.findViewById<Button>(android.R.id.button1)
+                    ?.isEnabled = editText.error == null
+            }
+        })
+    }
 }
diff --git a/src/all/mangadex/src/eu/kanade/tachiyomi/extension/all/mangadex/MangaDexIntl.kt b/src/all/mangadex/src/eu/kanade/tachiyomi/extension/all/mangadex/MangaDexIntl.kt
index d9263419c..64f544885 100644
--- a/src/all/mangadex/src/eu/kanade/tachiyomi/extension/all/mangadex/MangaDexIntl.kt
+++ b/src/all/mangadex/src/eu/kanade/tachiyomi/extension/all/mangadex/MangaDexIntl.kt
@@ -3,14 +3,19 @@ package eu.kanade.tachiyomi.extension.all.mangadex
 import java.text.Collator
 import java.util.Locale
 
-class MangaDexIntl(val lang: String) {
+class MangaDexIntl(lang: String) {
 
     val availableLang: String = if (lang in AVAILABLE_LANGS) lang else ENGLISH
 
-    val locale: Locale = Locale.forLanguageTag(availableLang)
+    private val locale: Locale = Locale.forLanguageTag(availableLang)
 
     val collator: Collator = Collator.getInstance(locale)
 
+    val invalidUuids: String = when (availableLang) {
+        BRAZILIAN_PORTUGUESE, PORTUGUESE -> "O texto contém UUIDs inválidos"
+        else -> "The text contains invalid UUIDs"
+    }
+
     val invalidGroupId: String = when (availableLang) {
         BRAZILIAN_PORTUGUESE, PORTUGUESE -> "ID do grupo inválido"
         else -> "Not a valid group ID"
diff --git a/src/all/mangadex/src/eu/kanade/tachiyomi/extension/all/mangadex/MdAtHomeReportInterceptor.kt b/src/all/mangadex/src/eu/kanade/tachiyomi/extension/all/mangadex/MdAtHomeReportInterceptor.kt
index 1aa2dfc8e..9c0a06d1b 100644
--- a/src/all/mangadex/src/eu/kanade/tachiyomi/extension/all/mangadex/MdAtHomeReportInterceptor.kt
+++ b/src/all/mangadex/src/eu/kanade/tachiyomi/extension/all/mangadex/MdAtHomeReportInterceptor.kt
@@ -5,6 +5,8 @@ import eu.kanade.tachiyomi.extension.all.mangadex.dto.ImageReportDto
 import eu.kanade.tachiyomi.network.POST
 import kotlinx.serialization.encodeToString
 import kotlinx.serialization.json.Json
+import okhttp3.Call
+import okhttp3.Callback
 import okhttp3.Headers
 import okhttp3.Interceptor
 import okhttp3.MediaType.Companion.toMediaType
@@ -12,6 +14,7 @@ import okhttp3.OkHttpClient
 import okhttp3.RequestBody.Companion.toRequestBody
 import okhttp3.Response
 import uy.kohesive.injekt.injectLazy
+import java.io.IOException
 
 /**
  * Interceptor to post to md@home for MangaDex Stats
@@ -28,37 +31,46 @@ class MdAtHomeReportInterceptor(
 
     override fun intercept(chain: Interceptor.Chain): Response {
         val originalRequest = chain.request()
+        val response = chain.proceed(chain.request())
+        val url = originalRequest.url.toString()
 
-        return chain.proceed(chain.request()).let { response ->
-            val url = originalRequest.url.toString()
-            if (url.contains(mdAtHomeUrlRegex)) {
-                val byteSize = response.peekBody(Long.MAX_VALUE).bytes().size
-                val duration = response.receivedResponseAtMillis - response.sentRequestAtMillis
-                val cache = response.header("X-Cache", "") == "HIT"
-                val result = ImageReportDto(
-                    url,
-                    response.isSuccessful,
-                    byteSize,
-                    cache,
-                    duration
-                )
+        if (!url.contains(mdAtHomeUrlRegex)) {
+            return response
+        }
 
-                val jsonString = json.encodeToString(result)
+        val result = ImageReportDto(
+            url,
+            success = response.isSuccessful,
+            bytes = response.peekBody(Long.MAX_VALUE).bytes().size,
+            cached = response.header("X-Cache", "") == "HIT",
+            duration = response.receivedResponseAtMillis - response.sentRequestAtMillis
+        )
 
-                try {
-                    client.newCall(
-                        POST(
-                            MDConstants.atHomePostUrl,
-                            headers,
-                            jsonString.toRequestBody("application/json".toMediaType())
-                        )
-                    ).execute().close()
-                } catch (e: Exception) {
-                    Log.e("MangaDex", "Error trying to POST report to MD@Home: ${e.message}")
-                }
+        val payload = json.encodeToString(result)
+
+        val reportRequest = POST(
+            url = MDConstants.atHomePostUrl,
+            headers = headers,
+            body = payload.toRequestBody(JSON_MEDIA_TYPE)
+        )
+
+        // Execute the report endpoint network call asynchronously to avoid blocking
+        // the reader from showing the image once it's fully loaded if the report call
+        // gets stuck, as it tend to happens sometimes.
+        client.newCall(reportRequest).enqueue(object : Callback {
+            override fun onFailure(call: Call, e: IOException) {
+                Log.e("MangaDex", "Error trying to POST report to MD@Home: ${e.message}")
             }
 
-            response
-        }
+            override fun onResponse(call: Call, response: Response) {
+                response.close()
+            }
+        })
+
+        return response
+    }
+
+    companion object {
+        private val JSON_MEDIA_TYPE = "application/json".toMediaType()
     }
 }