I am having this same issue. I have a 2018 Mac book pro. I had no issues. Two weeks ago i updated to Big Sur and almost instantly i started having problems. At first my keyboard stopped working a few times. Then I started having a blue or yellow tint over the screen. Now the screen has intense flickering of the yellow tint. It also has horrible image persistence. It is really bizzare. I have Run disk utility first aide, i have run diagnostics which said everything is fine, I have booted in safe mode, reset NVRAM, Reset SMC. Still the issues persist.