Changing user status to inactive requires expiration date change but no error message appears to tell you that

BNCF contacted me about this. They couldn't figure out how to make a user inactive, because whenever they set a user's Status to "inactive" and saved the change, the user would go back to being "active." From my testing it appears that if you change a user's Status to "inactive" you must also change their Expiration Date to today or earlier. Unfortunately, the UX does not give you an error message, it simply doesn't make the change. This is very confusing to users.

I have attached 5 screen prints that represent the steps I took in recreating and resolving the issue.