SO WHY DOES EVERY WEBSITE TREAT ME AS IF MY IP ADDRESS IS A SHITTY VPN?

For example, Pastebin just loops its captcha. 4chan keeps asking me to wait 120s.

This does not happen to my LTE subscription's IP. But that connection is too slow (40mbps only, I rarely use it).

Funnily enough, this does not happen when I start a private session (Firefox). Is there an add-on that is causing this?