Why is this blurry?

[Paul Stocum]

A side note but related: I always set my YouTube from auto resolution to 4K. Often in auto it will start out in 720 then ramp up to 4K after several seconds.

 

[Sollang]

Perhaps you inadvertently used the the Zoom option?

 

[Paul Harvey]

Perhaps you inadvertently used the the Zoom option?

Thanks but no, I did not use zoom.