I also just started having this issue on my Xbox Series S. I hosted someone else's experience, and then quit the game for an appointment I had. When I came back to try and reload the experience, the "Active Server" page came up. If I click "Join Match" it says I have the wrong password (I did password protect the server, but there is no place to enter a password on the "Active Server" page), and when I click "Take Down" I get a messaged saying an undefined error occurred. I also get the "Role Not Allowed" error. Thanks for your help.