Hi Bryan. I'm Greg, an installation specialist, 10 years awarded Windows MVP, and Volunteer Moderator, here to help you.
To change default webcam in Windows 10 from internal to External you only need to disable the internal cam in Device Manager, not set it as default in Devices & Printers (which is being phased out).
See the best tutorial on this here:
https://smallbusiness.chron.com/switching-lapto...
There will be more camera controls in the Camera app in the Start Menu All-Apps list:
https://www.digitalcitizen.life/how-use-camera-...
I hope this helps. Based on the results you report back I may have other suggestions if necessary. If you will wait to choose whether the problem is resolved, then I will continue to help until the problem is fixed
______________________________________________
Standard Disclaimer: There are links to non-Microsoft websites. The pages appear to be providing accurate, safe information. Watch out for ads on the sites that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the sites before you decide to download and install it.