TCL 55S403 Changes Volume (up/down) and Pause/Resumes On Its Own Randomly
Since the 9.2 update, I've experienced sporadic issues with the volume increasing and decreasing and the TV pausing/playing on its own. I've already ran a full factory reset and performed various tests with the remote control batteries removed.
Have you tried contacting TCL support yet to inquire further? I'd suggest starting there to see what options or suggestions they can provide. Each Roku TV manufacturer provides direct support for their products running the Roku OS.