Hi, I have been experiencing the same issue today when trying to accept. When I open the link (which for myself is still valid and does not state it’s expired), i click sign into apple account which then takes me to create an account. I click sign in again to just sign in. enter my apple id and password and enter. Once logged in after the 2 step authentication, the apple login page asks me to login again, in an endless loop. I am hoping to find a solution to this asap, and I have also tried all the above as troubleshooting too. thanks