Thanks for posting with a screen capture, @Don! Saved me a lot of work, 
since I signed on to ask about the same thing!
I’m also experiencing this if I choose either “all” or “none” after navigating to one of the sub-categories. I couldn’t replicate it here in meta, though.
My site is on Discourse 2.8.0.beta8, which seems to be the same as meta at the moment.
(Edited to add… @sam is like a ninja sneaking that fix in while I was still typing. 
)