Hi Tom..
Please don’t remove Elementor sites from the library..
It’s true, this is cause by elementor 3.0..and I see there is elementor update 3.01 but the problem remains.
However I just download older version elementor 2.9.14 than everything is back to normal.
I will continue using this method until the problem is solved. Please update the UNO theme to be compatible with latest version of elementor.
In my case, I create a site for my client using uno default.. After tweaking a few things on the layout, I can update to elementor 3.0 and everything is ok.