If you're on Mint still, that's X11 fucking you over. AFAIK, Mint hasn't moved to Wayland, though you might be able to install an experimental session, but I wouldn't trust it like a distro that's all-in on Wayland.
I used to contend with monitors jumping around like a jack russell terrier with X11, never keeping settings, dropping out due to ACPI. Wayland has fixed pretty much everything I had going wrong with that stuff.
Boot a live USB of some distros that default to Wayland like Fedora, and see how it reacts to screensaving, then make some choices from there.