Sure you can grab a copy of the empty project here
Dropbox - Demo_Corrupt_Layout.aprx
It doesn't really exhibit noticeable issues until you add a few dozen layers. Doesn't seem to matter if it's local or network data. It gets progressively worse with more layers.
The most common issue I would face with this project is UI hangs. For example I would get 30-45 seconds of UI greyout after doing something like "make this the only selectable layer". Drawing speed has always been fine.
Once the layout is completely removed from the project the issues are gone.
I hope this helps a bit with your research. I would appreciate a follow-up if possible.