Second pc display won't do anything other than mirror primary display

As the post title reads. It works to mirror the primary display only, so I know the cable is working. I'm on Windows. I've tried...

1. Changing the display properties in Windows display settings to extend or only show on display 2 (it goes straight back to display 1 only)
2. Reseating the cable on both ends
3. Using other ports on both devices
4. Deleting configuration and connectivity info in the registry for the second display and restarting my pc
5. Making sure Nvidia control panel doesn't have conflicting settings
6. Updating my display driver
7. Ensuring the settings my pc attempts to send to display 2 are usable hertz and resolution ranges for that display

It worked well around 3 months ago, then I didn't use the 2nd display for a while, but now coming back to it and trying again, it doesn't work.

Any advice for me out there? Thanks!