Which .plist File Stores Display/Arrangement Data?

I've been having problems since day 1 trying to run three monitors on a 2018 Mac mini. Apple replaced the logic board on the original mini I bought and that helped a little. I switched from mini DisplayPort to HDMI and that also helped a little. It was still quirky, with windows randomly bouncing around when waking up from sleep. Sometimes one of the displays would be gone and I'd have to reboot to get it back. It was a hassle but it was usable after fighting with it for the first few months. 

So here we are a few years later and up until recently, it was acceptably stable (although not actually stable. WTF Apple?). Suddenly I cannot get the system to see my 3rd monitor, the one that's connected to the mini's HDMI port. I unplug data, power, reboot the mini a million times. All combinations of these two. No matter what I do, I'm stuck with only two displays (1st world problem I know). 

I added a new volume to my mini, installed a fresh copy of Ventura on that, booted in to it and instantly, all three monitors work.

This is a pretty strong indicator that there is some .plist file somewhere on my real system that got corrupt and is preventing the computer from properly managing all three displays. 

And the point of this post is to ask if anyone *knows* which file or files that is? I could trial and error my way through this all day and find it eventually. But assuming my assumption is correct about this being the problem, if I knew which file it was, it could save me a ton of time!