it's funny how the butthurt Firefox users downvote me for just talking about my experience with the browser.

Nobody is downvoting you for just talking. They're downvoting you because you very clearly lack knowledge in what you're doing but are blaming it on the browser.

It might be a good idea to get a good VPN for any of those sites (even the streaming ones). No hate if you ran into an issue with FF. Every now and then I do see some PCs act weird with FF DNS options. Never able to figure out what causes them to not work correctly while most other PCs are working fine on the same local network. Opera and Opera GX "feel" too "busy" for me personally with just all the random things on the UI and features. I support people using anything that isn't official Chrome at this point.

If you don't already have a VPN, here is a list article with more than a few options and give some basic info on stuff like if they keep logs of IPs and for how long. Some of them also have additional DNS options for removing ads. https://torrentfreak.com/best-vpn-anonymous-no-logging/

firefox uses doh, not regular dns

Sounds like a typical layer 8 issue to me 🤔