@Tagging is broken

When I write or answer a post, I often want to tag another person.  For example,  here's my attempt to tag Jesse Dringoli: (Missing Media) .  It doesn't work.

Starting to write with the @ symbol used to trigger the Be Communities web site to pop a list of members.  What it does currently (05-Aug-23) is to list some arbitrary references to other posts, or other unwanted links.  It's impossible to create the tag to a human.

Using FireFox browser, which has always worked in the past (up to yesterday).