When in the Develop module my second monitor becomes blurry. This happened at the time of 10.2 update. I am running iMacPro and MacOS Big Sur 11.2.3. Interestingly, LR system info incorrectly shows I'm running MacOS 10.16.0.
iMacPro
64GB Ram
Radeon Pro Vega 64 16GB
LG Ultra Fine Display 27in - Secondary Monitor