Display, when connected, now automatically starts mirroring every time (macbook pro w/ventura)

I've been able to connect for the past few years my laptop to my external display multiple times a day just fine, where it treats the external display as I last set it up - an external display.

A couple days ago it started mirroring it. Every time I connect I now need to go into display settings, choose the external display, and Change "Use As" to "stop mirroring."

I have had a Macbook Air connected as well, with "use as" showing "Linked Keyboard and mouse." (I've tried disconnecting that, turning off 'handoff'. Oddly I can still move my cursor to the macbook air screen.) So not sure what the cause is but can't seem to find any solutions on the interweb. Any ideas?

Setup:

Connecting a Dell U3219Q external display

2019 Macbook Pro running Ventura (13.13.1 (a))