After a week long outage, my Tor bridge is fully functional again, but only after changing ports. Why?

The question is purely academic. I am not having technical issues and I am NOT asking for technical support.

I understand that technically, my ISP had probably choked the previous port.

I also know that some nation states, organizations or other actors - such as ISPs - block Tor connections for whatever (political?) reasons.

What I don't understand is what legal grounds they have to do this. I have read the Terms of Service. Twice. And there is nothing explicit about having specific ports blocked for whatever reason. It does say that they have the right to limit my bandwidth if they deem that my usage is impacting their other customers' connection negatively. Perhaps they somehow force it into this paragraph? As in, according to them, running a Tor relay doesn't count as "normal use"?

If you have any experience or knowledge on the matter, please advise. 😊

The question is purely academic. I am not having technical issues and I am NOT asking for technical support.