I'm currently posting this with TornTools enabled.
Tried a Hard Refresh as suggested by bogie, restarted browser after too, didn't help.
Names and ID don't work for me in the "search additional accounts" box.
Latest Firefox Version. PC. Happened before a fairly long time ago too, different browser.
EDIT: Refreshed twice and it started working again, then refreshed again and it broke, seems to be random but I think you could try to replicate with multiple refreshes?