Cannot expand or collapse subforums in main forum list

[Neophyte (OP)]

As title, clicking +/- either to expand a subforum that's collapsed or vice-versa doesn't work, it just reloads and snaps the focus to that subforum.  I've logged out, cleared pentarch cookies, logged in, "changed" my theme (since they're both default), no changes.  I use uBlock Origin but turned it off to no effect as well.

Firefox 81, Windows 10

[Neophyte (OP)]

bump - this is still an issue

[serger]

I can expand/collaps only News, Non-English and Info Center, all other subforums just have no +/- button.
Chrome 87, Win 7.
Cannot tell if that's the same issue.

[Erik L]

I've got collapse turned off for most of the categories.