I decided I wanted to try daily driving mint on my main machine and ever since install I've not been able to get the login screen to display properly on any one of my monitors. It'll always show roughly 45% of the screen on my smallest 1080p monitor. Tinkering with the "login window" settings got it working enough that I can kinda see the password field but no further. I haven't seen anything like this on the forums so I was hoping someone could help me out here.
This seems more like a display/video card/driver issue than a login setting issue. Have you tried other displays (with full reboot)? What's your graphics adapter?
Issue persists after full reboot. Graphics adapter is a Radeon 6700xt with appropriate Radeon driver installed.