I recently set up my new Mac Studio with my Samsung CRG9 external monitor, that supports up to a 5120 X 1440 resolution at 120Hz. I set my Mac Studio to run at that resolution and refresh rate, but for some reason whenever I wake my Mac from sleep, the refresh rate will switch to the "Variable (48Hz-120Hz)" setting. I don't want the variable refresh rate on this display, I would like it to just stick to the full 120Hz refresh rate at that resolution at all times because it makes moving things around the display a bit jittery when using the variable one. Not sure why it's switching back to variable after waking it from sleep but is there a way to prevent this?
Like I said, using a new Mac Studio running macOS 12.3.1, and a Samsung CRG9 external display.
I have this same problem. Apple "Help" guided me through turning my computer on in safe mode (I did not need this guidance by the way) and we were unable to change the behavior. They reverted to telling me to look it up in the monitor's manual as I'm using an Acer KG27U1. This is not acceptable support.
This seems like a fundamental development error on Apple's part. Users should be able to save settings and turn them off or on and not have them automatically and inevitably change. I look forward to Apple going bankrupt or them listening to their users and actually making something better instead of worse for once. Neither scenario seems likely.
P.S.- There is no way to turn off adaptive sync in my monitor settings. There is no option for anything relating to refresh rate in my monitor settings.
Using EasyRes (free at App Store) may be a workaround before Apple finally realize the problem is on their side.
Turning off FreeSync/AdaptiveSync on display's OSD is quite annoying as I also use my display for gaming on Windows, in which case VRR may be better. Also as others commented, not all displays can disable VRR. The problem is definitely Apple's fault.
I use external GPU and can confirm this problem still exists in Monterey 12.6.1 and Ventura 13.0, or at least with my eGPU setup.