What the title says. I get to the bottom of my first page of threads, hit the next button, and it this pulses for a while: 
Eventually it stops and nothing loads. I can go back to the first page and everything loads just fine. It’s been happening to me all day. The past ~12 hours or so. It’s probably me doing something incorrectly. Anyone have the same trouble? Windows 11, Firefox.
Just adding to the pile, experiencing the same under the followimg conditions:
I’ve observed this while on and off VPNs, from home and work connections, as well as wired and wireless.
I’m (not really) glad to hear others having issues. This started at the same time I started using mullvad vpn and I was worried I might have some issues to iron out there.