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 49be1bae74..cfbd2eb64b 100644
--- a/app/src/main/java/eu/kanade/data/category/CategoryRepositoryImpl.kt
+++ b/app/src/main/java/eu/kanade/data/category/CategoryRepositoryImpl.kt
@@ -52,7 +52,7 @@ 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 650331167a..9fcb8f79de 100644
--- a/app/src/main/java/eu/kanade/data/manga/MangaRepositoryImpl.kt
+++ b/app/src/main/java/eu/kanade/data/manga/MangaRepositoryImpl.kt
@@ -74,7 +74,7 @@ class MangaRepositoryImpl(
     }
 
     override suspend fun insert(manga: Manga): Long? {
-        return handler.awaitOneOrNull {
+        return handler.awaitOneOrNull(inTransaction = true) {
             mangasQueries.insert(
                 source = manga.source,
                 url = manga.url,
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 9523d9ffc6..4868d8d6f5 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
@@ -205,7 +205,7 @@ class DownloadCache(
     fun removeManga(manga: Manga) {
         val sourceDir = rootDownloadsDir.sourceDirs[manga.source] ?: return
         val mangaDirName = provider.getMangaDirName(manga.title)
-        if (mangaDirName in sourceDir.mangaDirs) {
+        if (sourceDir.mangaDirs.containsKey(mangaDirName)) {
             sourceDir.mangaDirs -= mangaDirName
         }
 
@@ -271,9 +271,8 @@ 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()
@@ -308,7 +307,7 @@ 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
@@ -320,7 +319,7 @@ class DownloadCache(
  */
 private class RootDirectory(
     val dir: UniFile,
-    var sourceDirs: MutableMap<Long, SourceDirectory> = mutableMapOf(),
+    var sourceDirs: ConcurrentHashMap<Long, SourceDirectory> = ConcurrentHashMap(),
 )
 
 /**
@@ -328,7 +327,7 @@ private class RootDirectory(
  */
 private class SourceDirectory(
     val dir: UniFile,
-    var mangaDirs: MutableMap<String, MangaDirectory> = mutableMapOf(),
+    var mangaDirs: ConcurrentHashMap<String, MangaDirectory> = ConcurrentHashMap(),
 )
 
 /**