What do to when playback crashes
If playback always stops a few seconds after turning off the screen, your system might be killing the app. Some vendors are known to be overly aggressive when trying to save battery. Try to add an exception for AntennaPod in the list of battery optimized apps.
We use Android’s built-in audio decoders. A lot of devices are shipped with rather buggy MP4 decoders that lead to various playback issues and even native crashes (think Bluescreen). In our opinion, your best option is to subscribe to MP3 feeds whenever possible.