Here's how I got it to work:
1) Very important: Play the short in YouTube, click "Share" on the right side of the video, and copy the link. This is a different link than what you'll find in other places.
2) Paste the link in the Video search box in Squarespace. You'll get an error, that's ok.
3) In the link you pasted, delete everything from the question mark and beyond. It's not needed. https://youtube.com /shorts/ypSbqqdiG28?si=SS4ENjJ0qZZFmTgw
4) Replace the word "shorts/" and the slash with watch?v=
https://youtube.com /shorts/ypSbqqdiG28?
https://youtube.com / watch?v=/ypSbqqdiG28?
5) When done it should be like this (Note: there are no spaces in the link, I put a space after .com to prevent the short form embedding here in the directions): https://youtube.com /watch?v=/ypSbqqdiG28?
