You may need to create a custom resolution with a smaller HZ range. My adaptive sync monitor would constantly go black at random during games until I changed it from something like 39hz-144hz, to 41hz-144hz instead.
You can Google it as it is a bit of a process requiring downloading a third party program to create the custom resolution but well worth the effort if it fixes your problem.
Edit: Actually you may be able to do it in the graphics control panel and don’t need a third party app. Been too long, can’t remember.