Xamarin ios push notification not working

I have a problem with push notifications on a xamarin project

situation: I have a working xamarin android / ios code with bundle id com.xxxx.abc.

I have to republish the same app with a different brand, I created a new plist, new registration on firebase, new google-service.plist file, but the notifications do not arrive as on the first app. Does anyone have similar experiences?

I checked the plist files are practically the same, even the project configurations (I created different configurations to change the themes, import the appropriate plist). I inserted a pop up when registering firebase and I get the fcmtoken even on apps that do not receive notifications