Since upgrading to macOS 12 Monterey from Big Sur I've had trouble with the LG 27UK650 4K monitor. Monterey recognises it as a 5K monitor and while it worked in 12.4 (the version I upgraded to) I had Macs losing it and I had to reset SMC of those to get it working again. I also noticed other problems in a Mac mini with certain USB devices which are not recognised after reboot and one needs to physically attach/detach before they are recognised.
Hoping that these bugs would have been fixed I upgraded to 12.5. But now the situation is even worse. The 27UK650 LG monitor was not getting a correct signal anymore. SMC reset worked once, but then it got lost again. SMC and NVRAM resets did not help as it had done in the past. While trying to see if some setting would fix it I turned on HDR in System Preferences for the monitor and that was an even bigger mistake. At some point WindowServer crashed and it would crash at every login attempt, effectively locking me out of my account.
I was able to fix this by using a second account on the system with admin privileges, using Terminal and sudo and cleaning out ~/Library/Preferences and ~/Library/Caches for the affected user. All preferences are lost, but at least I can log in. I opened System Preferences again and looked at Dimply preferences. After that, I could again not log in (WindowServer crashes on login) so I had to do my repair again.
Conclusion: macOS 12.5 is not stable and brittle in this respect. Stay away.
Hoping that these bugs would have been fixed I upgraded to 12.5. But now the situation is even worse. The 27UK650 LG monitor was not getting a correct signal anymore. SMC reset worked once, but then it got lost again. SMC and NVRAM resets did not help as it had done in the past. While trying to see if some setting would fix it I turned on HDR in System Preferences for the monitor and that was an even bigger mistake. At some point WindowServer crashed and it would crash at every login attempt, effectively locking me out of my account.
I was able to fix this by using a second account on the system with admin privileges, using Terminal and sudo and cleaning out ~/Library/Preferences and ~/Library/Caches for the affected user. All preferences are lost, but at least I can log in. I opened System Preferences again and looked at Dimply preferences. After that, I could again not log in (WindowServer crashes on login) so I had to do my repair again.
Conclusion: macOS 12.5 is not stable and brittle in this respect. Stay away.
