Thanks for the response. Just to follow up, prior to attempting this, I had to take steps on a more pressing AMD-related display problem (this one), and on restart my brightness buttons worked again. I had disabled auto-brightness via the UI, so it’s possible that combined with the restart might do away with the issue for me, but I might be speaking too soon. I’ll keep this in my back pocket for now but I cannot confirm at this time whether it’s the same problem.