Suddenly my Audacity is very slow

I have been working on producing an audiobook for the last two months. Audacity has been fantastic to work with, always quick to respond to my commands. Then, this morning, I downloaded and installed the newest update and suddenly I am getting program not responding messages when I try to edit my file. Does anyone have any idea why I am suddenly getting that? and that does not seem to be the issue. My problem started today after two months of 6-hour days and only after I installed the latest update.
Any ideas?

I can’t speak to the latest update as I have not installed that. But I recently ran into similar problems, I thought maybe it was because the size of my project file got to around 2GB, and Audacity isn’t compacting it even when I delete tracks. See Project file won't compact? .

This morning I deleted all but the essential tracks, selected them all, and copied and pasted them to a new project, which is now about 570 MB (there are 21 tracks now, the project is about 5 1/2 minutes long). I was then able to join two audio clips which I couldn’t before, although it took a lot longer than I feel like it should. However, when I tried to apply a “sliding stretch” effect which used to just take a few seconds I got the spinning circle and the “not responding” dialog and after 5 minutes of that I gave up. I don’t know what else to do at this point other than get Reaper or Cakewalk or some other DAW and be done with Audacity. It seems like when the project gets to a certain size and a lot of cutting and pasting and editing has been done that Audacity can no longer keep up, and even creating a “clean” project with fewer tracks doesn’t solve the editing problems that arise. But as to what the specific bug/failing is I don’t know, and I have not received any good answers on here.

I have experienced both of these problems with the latest update. " program not responding messages" when compressing. As well as projects that are typically 1.2gb ballooning to over 7gb.
I’m running the Audacity app image audacity-linux-3.5.1-x64 on Ubuntu 23.10