So I upgraded to win 11, and my monitor didn't register at all (SP Pro 7 on Philips 43m6b 4k60Hz).
The monitor wasn't even recognized in Windows.
I thought the problem was different, since the symptoms were different, but after spending multiple hours(!) on trying to find the solution, I did a hail Mary and reinstalled the 2019 drivers again.
This .. eh .. circumvented (I refuse to say fixed) the problem.
At first it recognised it with 640*480 (which was already progress) but after running the registry script, and a reboot, it showed in 4k.
Honestly, what does it take, Microsoft, to get this fixed?