2024 yukon rear entertainment screens won’t connect to onstar wifi

We have a 2024 yukon xl at4 with the rear entertainment screens.  The screens respond as if we do not have an on star account. Been at the dealer for weeks at a time and waiting for GM or Onstar engineers to call. Total incompetence. Spent hours on phone with on star. Reset everything dozens of times. Dealer has talked to on star. Dealer tries something and then says they should hear back from GM or on star in 1-3 days. No solution in sight. Beyond frustrating. Anyone have any ideas?