[Copying my post from another thread on this, in case cross-referencing the two might yield anything for all at some point...]
Same problem here, with Surface Go 2 & Brydge keyboard. Grr!
I had an online chat last week with a lovely young man on SS support about not being able to edit, but iirc I didn't explicitly say that I was using a Surface device - it only just occurred to me that that might be an issue.
I found a couple of reddit threads which include some fixes which seem to have worked for others. They didn't for me, alas (& nor did those above), but posting here in case it's of use to anyone still struggling on this thread.
https://www.reddit.com/r/squarespace/comments/j6oat6/psa_for_anyone_with_a_microsoft_surface_or/
https://www.reddit.com/r/squarespace/comments/eysfh1/editing_not_working/