Tomorrow’s day 21! I meant to update this before, right after the original post I used wax from an unscented tea candle to seal in the crack, which was around the entire egg. I candled it right before lockdown and the chick inside was definitely moving and looked to be around the right size. Thank you for that advice! I wouldn’t have thought of it.
When I took it out of the egg turner though, a chunk of the outer shell stuck to the plastic. It was really hard to get it out.

it’s a little giant incubator/egg turner. Next time I’ll try to put a paper towel or something in between the wax and the turner. Hopefully the missing shell won’t be an issue- the membrane is still in tact and right now it’s the most wiggly egg at lockdown. (Top right of photo 2).
Can’t wait to see if this little one hatches.