So, not totally sure but it is Visual Studio, so who knows. I rebooted a few times, cleaned out the bin and obj for both the main MAUI app and the Class Library it references. Rebooted again. Then after bringing VS up, I tried to just run debug in Windows, but failed stating that my Class Library couldn't deploy do DEV. Of course not, its a Class Library.

To fix that I had to change the default app identifier from com.companyname.appXXXXXX to something else.

Finally got it all working again.