Weird issue with display resolution

[Alitheros]

So I have been playing for YEARS, and always at 3840x2160 full screen. No issues this morning. Let Windows install the latest round of updates, then when I launch FFXIV I get to the title screen (at 3840x2160) and I can no longer interact with it. The mouse moves around but nothing is 'clickable'.
After some messing around I found this issue only exists in that specific resolution, if I back down to 1920x1080 everything works (of course all my UI settings are completely messed up as a result of scaling).
I tried installing the latest NVIDIA drivers just in case, but I can't think of anything I can do to fix this. I really don't want to have to drop down to 1920x1080 because it looks terrible.
Anyone else ever experience this? Any ideas on a fix?

** Edit **
I was able to fix the issue by disabling and then re-enabling DSR in the Nvidia control panel. My display is not native 3840x2160 so it relies on DSR to actually utilize that resolution. Not sure how that got messed up but fingers crossed I'm good now. Keeping this post in case this random thing happens to someone else!