Same here. I've tried to sync Square with Etsy. I did every step in this Etsy article: https://help.etsy.com/hc/en-us/articles/360000905467-How-to-Use-Square-in-Your-Etsy-Shop?segment=sel...
But the SKUs and stock are never imported to Square from Etsy nor sync. I've read many discussions posted from 2018 to the most recent; sadly, no solution in the past and now.
One of the advice from the older post, I think may be helpful if you are looking for selling in person in local market or craft show, is that deactivate the product listings you want to sell on the market, and reactivate them after the market activity ends.
Also, be aware that "If you process a payment for an item that's not among your synced Etsy listings, you'll be charged a $0.20 transaction fee, which will show up on your Etsy bill as a 'Square manual' fee."
