On my TCL 65r625, when using the headphone jack, as I exclusively do, music comes out of only the right channel. Not voices or anything else. I've tested the TV speakers and they work as they should, music comes out of both sides. I've set everything to stereo output, but it doesn't fix the problem.
Yes, hardware-wise everything is copacetic. I just found that when watching a show through Fandango, I was able to use the Roku menu while the episode was playing and switch the audio track from track 2(surround) to track 1(stereo). Even though stereo was already set in the main Roku settings, when watching shows and movies, sometimes I guess there's multiple audio track options. Unfortunately, the Apple TV+ app does not give any audio track options, it only plays in surround, so the problem is unfixable with that app.