The problem is simple, after updating to BIG SUR 11.1, Apple programmers "broke" something and since then BIG SUR no longer recognizes external 4k monitors via direct ThunderBolt 3 connection!
Here is the example image (taken from the Apple discussion forum), since then a slow agony with consequent productivity problems towards professionals who are no longer able to work as before.
This causes problems of incorrect resolution, completely wrong monitor size and frequency always at 30hz. Practically the monitors are UNUSABLE!
An absolute shame from Apple, perhaps the
most serious bug in history that is not taken seriously.
This is the classic and real "gate", bigsurmonitorgate.
All the sites and blogs have talked about it, but Apple still doesn't care today and even the big sur 11.3 beta has not been solved!
THERE ARE NO WORDS!