Always update fresh data from source if manga isn't favorited

domain/src/main/java/tachiyomi/domain/manga/interactor/NetworkToLocalManga.kt

@@ -1,6 +1,7 @@
 package tachiyomi.domain.manga.interactor
 
 import tachiyomi.domain.manga.model.Manga
+import tachiyomi.domain.manga.model.toMangaUpdate
 import tachiyomi.domain.manga.repository.MangaRepository
 
 class NetworkToLocalManga(
@@ -14,6 +15,11 @@ class NetworkToLocalManga(
                 val id = insertManga(manga)
                 manga.copy(id = id!!)
             }
+            !localManga.favorite -> {
+                // if the manga isn't a favorite, update new info from source to db
+                manga.updateManga(localManga.id)
+                manga.copy(id = localManga.id)
+            }
             else -> {
                 localManga
             }
@@ -27,4 +33,14 @@ class NetworkToLocalManga(
     private suspend fun insertManga(manga: Manga): Long? {
         return mangaRepository.insert(manga)
     }
+
+    private suspend fun Manga.updateManga(id: Long) {
+        mangaRepository.update(
+            toMangaUpdate()
+                .copy(
+                    id = id,
+                    thumbnailUrl = thumbnailUrl?.takeIf { it.isNotBlank() },
+                ),
+        )
+    }
 }

domain/src/main/java/tachiyomi/domain/manga/model/Manga.kt

@@ -72,15 +72,6 @@ data class Manga(
         return chapterFlags and CHAPTER_SORT_DIR_MASK == CHAPTER_SORT_DESC
     }
 
-    fun shouldUseNetworkMangaInfo(networkManga: Manga): Manga =
-        if (!favorite) {
-            // if the manga isn't a favorite, set its display title from source
-            // if it later becomes a favorite, updated title will go to db
-            copy(title = networkManga.title)
-        } else {
-            this
-        }
-
     companion object {
         // Generic filter that does not filter anything
         const val SHOW_ALL = 0x00000000L