It has been requested a few times, but after over 3 years, there’s still no option in the settings to set a default repeat option. Every single time I get into my car and play music, the music will stop at the end of the album.
Both of those forums topics are quite old and had very little comments. The feature request which is what Plex uses to guide if a feature should be implemented only has 7 votes. There doesn’t seem to be much interest in this feature, so it’s unlikely to get implemented.
I used to use Google Play Music for streaming from my phone because Plex will often throw errors about playback, currently-playing track will de-sync from my car’s display causing me to have to “next track” on the car for the correct track name to appear on my headunit, etc. Since Google Play Music is dying soon and Youtube Music leaves a lot to be desired, my plan was to use Plex, but so far, it’s not been going well either.
On GPM, the repeat option is just remembered between playbacks. If I set it to repeat all, whenever I build a playlist, play an album, etc., it will repeat all.
Not saying it won’t, but just not a high priority with such little interest. If there’s ever any other work related to the repeat feature, this may get implemented for free if it’s not too complicated.