Maybe this will help someone.
I managed to downgrade from 12 to 10.1.0.121, after that did the whole thing with Googlefier and had problems for the first step before sign in to google account. I found out that with year 2022 the button 1 is not active. 2021 worked.Next step before sign in changed the date to automatic.
After so many tries there were GMS on the phone but with "this device isn't play protect certified" errors
Finally the fix that worked (fot now 1 day )is this:
https://ictfix.net/google-for-huawei/ solution 3
I am not owner of the site just found Googling.
Interesting, mine is working for more than 3 hours now.