I did everything fresh. The reason I did was because each page tbey returned had something printed on the bottom, and the green letter said "new filing". My husband wanted to just send the returned stuff with new check. I tried emailing and calling uscis but got nowhere so just decided to re do everything fresh. And we also decided to use credit card for payment instead of the check. Hopefully it doesn't get rejected this time, as green card expires on the 27th.
Thanks and good luck to you as well!
(2020 was actually an excellent year for us, my husband got his visa and was able to move here, we bought a house, our twins were born, I was lucky to be layed off and get unemployment due to pandemic so my husband didn't have to work and was able to stay home with me and the newborn twins. We got extremely lucky with how things went down, could have been catastrophic though)