Filtering is not working for me at all, in a bizarre way.
When I click on it, the box shows the keyword field already filled in with an email address (not mine, but that of a family member). Because the keyword field is already filled, I can't see anything else.
A workaround that works only sometimes is to delete that email address in the keyword field and hold down the Backspace key -- if I just delete the email, it shows up right away. Even then, I usually can't see all my labels.
This happens on Chrome, but not on Firefox. Please don't make me switch to Firefox.