I too use eastlink,had an account number change there, and had to get eastlink chat support to update the account number within my streaming account, which fyi is separate website from your main account.
Now I can view all my gl9bal channels through my zfold phone, firestick, and my win 10 laptop - but Hisense tv only shows some subscribed channels which is annoying as heck since it's our main viewing device. I've cleared the tv's cache, powered it off by unplugging it, removed and reinstalled the app, to no avail.
Cruddy Hisense, no way to update this model if that's the issue, and it doesn't show some pluto channrls either that all other devices do.