Hello, my name is XXXXX XXXXX I am here to assist you.
I see your problem, I dont use that particular model but am aware of a change that was made on the servers that made the current plugin incompatible with the servers, you need to go into your account from a pc and make some minor changes to your account and then update on your radio. Here is how below.
you need to update your password XXXXX it's compatible with the TTR1. You may also need to update your username if it's longer than 20 characters. Visit https://care.siriusxm.com/login_view.action
and sign in using your account username and password. Follow the instructions to update XM Radio Online username and password information. Always use the latest software update for your TTR1 located in the Software Update section in the System Setup option in the main TTR1 menu.
After doing this let me know if it is able to update and connect afterwards, ensure to change username and password XXXXX the desktop radio after changing it online.
For more information read this article.