It has been 2 days. It happened yesterday, my Shield TV couldn't load any channels, I thought something wrong with my Shield TV, then I reboot the router and did reset on the Shield TV, also installed/used different IPTV app, I could see the channel list, but still won't load any channel. I also reset and changed the Rocket portal from p2 to p7, and p6, still won't work. I'm sure it not ISP issue since I have another Shield TV with IPTV66, it's working fine.
The app I use is Titvmate, it has error code 401, means: using the incorrect credentials or lacks valid authentication. So I went to check the donation code, it shows the code is active and no issues. Am I missing something here?

Anyone has the same issue? Any suggestions? Thanks