How many simultaneous streams are allowed? I think it’s 20, right?

How many simultaneous streams are allowed? I think it's 20, right?

When I try to watch on more than 3 devices, I get an error saying that I've exceeded the maximum number of simultaneous streams outside the home. But this isn't correct, because I haven't actually gone over the limit. I just need 5 btw

Do I have to set a new home address everytime?

Does anyone know the detailed rules for how this part works? I guess I must be doing something wrong.

Thank you for your help, everybody.