Fair warning if the show or parts of it do come back, Do Not try to continue with the edit. Projects become brittle after a failure and are prone to failing again. Select each track and File > Export > Export Selected Audio as WAV files and start over.
There is an odder technique of opening up two Audacity windows and Copy/Paste the pieces to a fresh window. You can try that after you export your work as WAV files.
This is why users are asked to post their audacity versions when they make a post.
I’m confused. If you have an .aup file, you are using 2.4.2 or prior, and my previous comments should be valid.
If you have 3.1.3 (3.0 and up) you will have an .aup3 file. If this is the case, zip up your .aup3 file and upload it to a public file sharing service, post (or PM me) a link; I’ll take a look at it.
And for today ONLY, I’ll extend the offer to your .aup file. Zip it up, etc.