When I load some Cubase projects, the lock icons on some collapsed folder tracks show an incorrect state.
Specifically, they indicate that at least some of the tracks in the folder are unlocked, like so:

When I then click the folder icon to open the folder track, the icon switches to the correct state (showing that all tracks in the folder are indeed locked):

This is the workaround, because the lock icon will keep showing the correct (locked) state even after closing the folder track again.
Not the end of the world, but it’s these fit-and-finish bugs that make you wonder what else may lurk in the code, and that (perhaps unfairly) tarnishes the quality perception of the product.
This is on Windows 11 and Cubase 14. Don’t know if this is still an issue in Cubase 15, since that version just wasn’t compelling enough for me to deal with the hassle of upgrading. I’m looking forward to Cubase 16 to make an upgrade worth my while.