As I said, when trying to open a downloaded video the app crashes immediately with the following log:

java.lang.RuntimeException: setDataSource failed: status = 0x80000000
	at android.media.MediaMetadataRetriever._setDataSource(Native Method)
	at android.media.MediaMetadataRetriever.setDataSource(MediaMetadataRetriever.java:313)
	at android.media.MediaMetadataRetriever.setDataSource(MediaMetadataRetriever.java:254)
	at android.media.MediaMetadataRetriever.setDataSource(MediaMetadataRetriever.java:359)
	at com.github.libretube.util.OfflineTimeFrameReceiver.<init>(SourceFile:18)
	at com.github.libretube.ui.activities.OfflinePlayerActivity$playVideo$1.invokeSuspend(SourceFile:595)
	at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(SourceFile:9)
	at kotlinx.coroutines.DispatchedTask.run(SourceFile:116)
	at android.os.Handler.handleCallback(Handler.java:938)
	at android.os.Handler.dispatchMessage(Handler.java:99)
	at android.os.Looper.loopOnce(Looper.java:226)
	at android.os.Looper.loop(Looper.java:313)
	at android.app.ActivityThread.main(ActivityThread.java:8663)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:571)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1135)
	Suppressed: kotlinx.coroutines.internal.DiagnosticCoroutineContextException: [StandaloneCoroutine{Cancelling}@d19729e, Dispatchers.Main.immediate]

I already tried to reinstall the app from scratch, clean the cache, download the videos without using proxy, change instance and download them from another (although I think all downloads are directly from Youtube anyway) and still nothing helps, it always crashes the same. Investigating a little in the Libretube Github I didn’t find anyone else with a similar problem (or I didn’t see it), but until recently I started to have this problem that I didn’t have before.