I've been using this feature for gaming for a few months now with very little issues, but for the past week or so that hasn't been the case.

Now when I try to do things on my other monitor, the game on my main monitor will freeze completely until I move back and interact with it. I think maybe a recent DisplayFusion update or driver update might have borked it since it used to work so perfectly.

That's what I thought as well but I reverted back to 5.0 and the problem persisted. Is there a way to do a "clean install" just to be sure that's not the issue?