HBOMax Login Stopped Working -- ATT Subscription Expired

Very frustrated.  I came over from TMobile/Sprint when purchasing a new iPhone 13 primarily because the cost of the more expensive AT&T wireless plan was pretty much offset by the $15/mo value of HBOMax AT&T was offering as part of their Unlimited Elite plan.

When the wireless service was added to my AT&T account (I already had phone/internet) I activated HBOMax and it worked fine for 30 days and then I could not log in.  HBOMax info said my subscription had expired.  

I have tried multiple phone calls and spoken with multiple reps and tech support, incl. at HBO (who of course blames everything on an AT&T problem).  I have tried everything suggested by customer service and in searching these forums.  I have had service tickets "elevated" at AT&T and HBO.  No one seems to be able to get my HBOMax re-synced with AT&T.  Searching these forums I see so many people with this or very similar problems ... all frustrated at the poor tech here.  I feel I made a huge effn mistake switching services. 

If anyone has seen some resolution to this (or a similar activation problem) please comment away.