Why is QuickTime downscaling 1080p USB video to 640x480 on iMac?

So I have deleted the plist files and other files found in Library that are associated with QuickTime, and retried recording with the same problem as above.

Next I started up in Safe mode, and then tried again to record, and this time, the resolution did bump up to 1080p as it should. However, the video was extremely blurry.

I then booted normally and tried QuickTime again, and this time I am getting the correct size of the video as I did in Safe mode, however it is still blurry.

I have OBS installed, and on a whim I tried OBS and it also gets the correct resolution with a bonus that the video input is NOT blurry anymore!

things that make you go hmmm!

So I'm halfway there now, just need to find out how to fix the blurry in Quicktime record!

Any one any ideas for blurry video in QuickTime?

Thanks!

the USB video device puts out 720p 60fps in high mode and 1080p 30fps in max mode. so it isn't interlaced. Yes you are correct that OBS is OBS studio.

A few months ago, I don't remember exactly, QuickTime on my iMac referenced above worked fine, at both 720pand 1080p video capture. Also as noted, my Intel Mac mini continues to capture fine in 720p as well as 1080p with no blurring.

I am running latest macOS on both the iMac as well as the Mac mini.

Thanks!