Have recreated the issue so thank you for bringing to attention. It's not the vimeo embed but with the row gutter 1% not being applied on smaller screens.
You can see here it behaves exactly the same.
https://rickei3.dreamhosters.com/video-cropping-test/
Screen Shot 2022-01-03 at 7.07.22 PM.png Screen Shot 2022-01-03 at 6.56.30 PM.png
I have forwarded to Armin for further inspection but in the meantime let me know if this suits:
.row.one-col-row.row-1 { margin-bottom: 1% !important; }Code added to > Customize > CSS
Result, 1% is kept:
Screen Shot 2022-01-03 at 7.17.36 PM.png