Fix download ahead

Fixes #9669

app/src/main/java/eu/kanade/tachiyomi/ui/reader/ReaderViewModel.kt

@@ -25,6 +25,7 @@ import eu.kanade.tachiyomi.data.track.TrackManager
 import eu.kanade.tachiyomi.source.model.Page
 import eu.kanade.tachiyomi.source.online.HttpSource
 import eu.kanade.tachiyomi.ui.reader.loader.ChapterLoader
+import eu.kanade.tachiyomi.ui.reader.loader.DownloadPageLoader
 import eu.kanade.tachiyomi.ui.reader.model.InsertPage
 import eu.kanade.tachiyomi.ui.reader.model.ReaderChapter
 import eu.kanade.tachiyomi.ui.reader.model.ReaderPage
@@ -449,7 +450,7 @@ class ReaderViewModel(
         val manga = manga ?: return
 
         // Only download ahead if current + next chapter is already downloaded too to avoid jank
-        if (getCurrentChapter()?.pageLoader?.isLocal == true) return
+        if (getCurrentChapter()?.pageLoader !is DownloadPageLoader) return
         val nextChapter = state.value.viewerChapters?.nextChapter?.chapter ?: return
 
         viewModelScope.launchIO {