Video works in Web Browser, but not on firestick or android phone app

Are you using Android beta apps? I discovered a flaw in the recent beta which didn’t allow me to Direct Stream most of my .ts recordings. Switching to transcode solved the playback issue, which might be happening when you switch off your WiFi.
I link my thread for @BigWheel, maybe it helps drawing a conclusion. If this is something different, just ignore it: