When you toggle "Inherit languages from project settings." and delete a few languages, with it unchecked it preserves the modified list of languages rather than presenting you with the full inherited list again.
Steps to Reproduce:
1. Go into a project and select one
2. In the Languages tab, select "Manage languages" from the right dropdown
3. See checkbox for "Inherit languages from project settings."
4. Uncheck it, see a bunch of languages show up
5. Remove a few languages
6. Change your mind and re-check "Inherit languages from project settings."
7. See number of languages restored to number it inherits, good
7. Change your mind again and check it
8. Deleted languages don't return and you have the lower number, huh
What I expected to happen was the deleted languages return and begin again to delete them down to what I want to use.
Additional info: This may be the intentional behavior rather than a bug, but if so it would be great to see documentation or some kind of note on the screen to explain what's happening. In the current form it was confusing and you can't easily go back to defaults after deleting languages (you have to manually look at the project languages list add them back one by one).
Or you could have an additional button to say "Reset inherited languages from project settings." or something when the box is unchecked so you can easily restore defaults.