Hi Meaghan, thanks for your prompt reply. I did some troubleshooting, took all the screws out and removed the battery and found the cover went back on (still stiffer than the video but it did). So I took the cover back off and put the battery back in then started putting the screws back in place, trying to put the cover back on one screw at a time.
Turns out one of the screws holding the battery in place is stripped and was sticking up just enough to block the case from going back on. I suppose it’s not a huge deal if I’m only using 5 of the 6 screws holding the battery in place.
Anyway, battery is in, cover is on and my phone seems to be working. I definitely won’t be trying to open this phone again unless it’s to replace an internal part.
Thanks again for your help.