Another thing that happens a lot but I can’t reproduce it reliably:
When moving files around inside a package, rarely all the filenames become lowercase. This of course prevents scripts from running etc., and is super annoying (if you move a folder with subfolders and 100s of scripts in them and suddenly all are lowercase).
It’s still happening, almost every day, but not 100% of the time. That you could not reproduce it does not mean that it doesn’t happen, you just need to look harder.