diff --git a/app/src/main/java/eu/kanade/data/category/CategoryRepositoryImpl.kt b/app/src/main/java/eu/kanade/data/category/CategoryRepositoryImpl.kt
index 5bb792ff7..5cc7f1ad9 100644
--- a/app/src/main/java/eu/kanade/data/category/CategoryRepositoryImpl.kt
+++ b/app/src/main/java/eu/kanade/data/category/CategoryRepositoryImpl.kt
@@ -55,7 +55,7 @@ class CategoryRepositoryImpl(
     }
 
     override suspend fun updatePartial(updates: List<CategoryUpdate>) {
-        handler.await(true) {
+        handler.await(inTransaction = true) {
             for (update in updates) {
                 updatePartialBlocking(update)
             }
diff --git a/app/src/main/java/eu/kanade/data/manga/MangaRepositoryImpl.kt b/app/src/main/java/eu/kanade/data/manga/MangaRepositoryImpl.kt
index d64532c13..be2b78c07 100644
--- a/app/src/main/java/eu/kanade/data/manga/MangaRepositoryImpl.kt
+++ b/app/src/main/java/eu/kanade/data/manga/MangaRepositoryImpl.kt
@@ -78,7 +78,7 @@ class MangaRepositoryImpl(
     }
 
     override suspend fun insert(manga: Manga): Long? {
-        return handler.awaitOneOrNull(true) {
+        return handler.awaitOneOrNull(inTransaction = true) {
             // SY -->
             if (mangasQueries.getIdByUrlAndSource(manga.url, manga.source).executeAsOneOrNull() != null) {
                 return@awaitOneOrNull mangasQueries.getIdByUrlAndSource(manga.url, manga.source)
diff --git a/app/src/main/java/eu/kanade/tachiyomi/data/download/DownloadCache.kt b/app/src/main/java/eu/kanade/tachiyomi/data/download/DownloadCache.kt
index 1dfd51576..1f8a88ea3 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/data/download/DownloadCache.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/data/download/DownloadCache.kt
@@ -220,7 +220,7 @@ class DownloadCache(
     fun removeManga(manga: Manga) {
         val sourceDir = rootDownloadsDir.sourceDirs[manga.source] ?: return
         val mangaDirName = provider.getMangaDirName(/* SY --> */ manga.ogTitle /* SY <-- */)
-        if (mangaDirName in sourceDir.mangaDirs) {
+        if (sourceDir.mangaDirs.containsKey(mangaDirName)) {
             sourceDir.mangaDirs -= mangaDirName
         }
 
@@ -286,9 +286,8 @@ class DownloadCache(
                         val mangaDirs = sourceDir.dir.listFiles().orEmpty()
                             .filterNot { it.name.isNullOrBlank() }
                             .associate { it.name!! to MangaDirectory(it) }
-                            .toMutableMap()
 
-                        sourceDir.mangaDirs = mangaDirs
+                        sourceDir.mangaDirs = ConcurrentHashMap(mangaDirs)
 
                         mangaDirs.values.forEach { mangaDir ->
                             val chapterDirs = mangaDir.dir.listFiles().orEmpty()
@@ -325,7 +324,7 @@ class DownloadCache(
     /**
      * Returns a new map containing only the key entries of [transform] that are not null.
      */
-    private inline fun <K, V, R> Map<out K, V>.mapNotNullKeys(transform: (Map.Entry<K?, V>) -> R?): MutableMap<R, V> {
+    private inline fun <K, V, R> Map<out K, V>.mapNotNullKeys(transform: (Map.Entry<K?, V>) -> R?): ConcurrentHashMap<R, V> {
         val mutableMap = ConcurrentHashMap<R, V>()
         forEach { element -> transform(element)?.let { mutableMap[it] = element.value } }
         return mutableMap
@@ -337,7 +336,7 @@ class DownloadCache(
  */
 private class RootDirectory(
     val dir: UniFile,
-    var sourceDirs: MutableMap<Long, SourceDirectory> = mutableMapOf(),
+    var sourceDirs: ConcurrentHashMap<Long, SourceDirectory> = ConcurrentHashMap(),
 )
 
 /**
@@ -345,7 +344,7 @@ private class RootDirectory(
  */
 private class SourceDirectory(
     val dir: UniFile,
-    var mangaDirs: MutableMap<String, MangaDirectory> = mutableMapOf(),
+    var mangaDirs: ConcurrentHashMap<String, MangaDirectory> = ConcurrentHashMap(),
 )
 
 /**