The only problem I had with Firefox 89 was with streaming Youtube videos and that was solved / fixed by disabling hardware acceleration in the Firefox 89 settings.I wondered about FF 89 too, but I've had it 2 or 3 days without this trouble. I'm still not sure though.
What I've found so far is that if you use HTTPS instead of HTTP, it will only delay a bit and then let you in without the captcha. Give it a try. Maybe bookmark the HTTPS address.
Right On!But, the key takeaway is not to worry, not to fret. It's nothing more than a CF (a CDN) interruption. Just authenticate and tolerate it until it goes away. It's nothing to be alarmed about and the admin will know about this when they see their messages.