With pypush the error seems to come when generating validaiton data (it either gets stuck endlessly or shows a error saying no cert found). Pypush is still able to communicate with apples sms gateway (and the gateway still sends sms replies). Additionally 2fa codes are still triggered and sent.
The weirdest part is even if you import your own real mac serial (data.plist) the same issue arises (I tried with my personal 2011 mac mini).
I wonder if the issue specifically relates to pypush trying to spoof a m1 mac using a intel mac serial, or the uncanny vally of registering a phone number through a mac serial.
Apple charges him $0.50 USD per install for the store.
https://rileytestut.com/blog/2024/04/17/introducing-altstore-pal/