Dan,
One thing you haven't mentioned is if you cleared the Groups.io
cookies on all the computers and browsers you use(d) so you can
(forcefully) start a brand-new fresh session and see if that clears
it, if you haven't give that a shot, maybe something incorrect has
gotten cached somewhere locally.
Another possibility to help clarify if it's on your local end,
temporarily change your groups.io password, find someone
trustworthy* outside your ISP area, and let them login as you and
see what they get onscreen.
If they get the same strange result then it must be some data
corruption in the groups.io database, I doubt code changes would
create this type of random weirdness, and the doesn't seem to indicate it
could somehow create this.?
If they get the correct result then it has to be something on your
end.
Cheers,
Christos
* I can help with that if you want.