Motorola Moto G — After restart, my music playlists are corrupted.

I have a Moto Z3 (Android 9). I recently started having issues with my music playlists loosing songs after I restart my phone. For example, I have 1 playlist with 157 songs. But now it shows only 54. All music is stored on the phone. The only way to temporarily fix the issue is to delete the playlist and then copy over (from PC) the playlist back to my phone. This only works until I restart my phone again. I have tried the following, but nothing so far fixes the issue:

1) Moved music files and playlist files to internal storage from SD card.
2) From Google Play Music, reset app cache and refreshed.
3) Tried other music player.
4) Performed a factory reset on the phone.

The playlists I import are m3u files. Also after a restart, Google Play Music initially shows "No Downloaded Music". Then the playlists slowly start reappearing and are initially empty.