I'm mainly using my new TCL r625 as a PC monitor. I've barely had it for 2 days.
Twice now I have had brightness controls stop responding. They just get stuck on Darker. The only solution I've been able to find so far as been factory resetting. This is ridiculous if I'm going to have to do a reset every day just to change the brightness levels around
As far the issue you're seeing, when does this occur?
What function are you performing on the TV when you are trying to change the settings and encounter this behavior?
Are you streaming video inside a channel? If so, which channel?
Are you displaying standard, HDR, or Dolby Vision content?
In Settings>System>Advanced system settings>Factory reset, there is an option to 'Reset TV audio/picture settings'. This does not perform a full factory reset, but allow you to reset the settings adjustments on the TV. This should help you avoid needing to perform a full factory reset.