I don't even use a VPN. It still allows me to view subreddits and my own account, but this happens when I try to enter a comment section. Fuck reddit, I hardly ever post there these days, but damn it I do need access to the information in their comments sections pretty often for a variety of reasons.

What's more, it's only happening on Firefox. I downloaded and installed chrome and everything is normal on that browser.

Edit: Clearing cookies fixed it. Leave it to reddit to give you a page that's like "lol fuck you we banned you piss off" whenever their site has a bug and shits the bed