The recall channel, aka back button, previous channel on my Samsung remote stopped working about a month ago. Sesrched for answers, found other comments w/same problem. Commented on another post with solution I found & reposting in hope to get word out as it was sooo Frustrating!! I tried all the button reset options etc nothing worked. So, in settings I reset the TV to default hoping that would work. During the reset steps and voice accessibility set up, I opted for Bixby (vs Alexa) for the voice commands, and when prompted to use the voice button to say "previous channel". It worked! Thank gosh, I was getting so angry and frustrated the return button not working. At least now I can get Previous Channel! A little extra effort to 'say' it than pushing a button, Lol. You probably Don't need to reset tv like I did. I suggest just trying voice command, and use Bixby (which is Samsungs AI) if Alexa doesn't work. Hopefully the next firmware update will fix issue. Good luck.
