This problem is back with 551.76 and the one before 551.61.
Going back to 551.52. I will report if there is any difference with freezing after 20 minutes using DX12.
EDIT: I also have the freeze after 20 minutes with 551.52.
Installed 551.23. Runs stable so far for more than 60 minutes.
Can anybody confirm for march 2024?