did it make any difference on your side after adding these headers? I already have all these headers in place but can't get the pass to be updated on the device. no errors on log endpoint.

Adding additional details , I can also see the device tries to pull the pass for somewhere around 20 attempts and then eventually that pass becomes non updatable. Even if you trigger notification to update the pass after the above attempts , the call to retrieve serial number occurs but after that it doesn't make call to /v1/passes endpoint to update the pass.

do you send the change text in the updated pass? If not, that might be the reason it is not being displayed.