mrktmind Push notifications will be delayed because Play services not allowed to run in background
This is almost certainly your problem.
There was a recent change to how the Google Play sandbox works. I may get the technical details a bit wrong here, but there used to be a GrapheneOS system service that ran in the foreground, and (as a side effect) kept Play Services running. This is no longer the case, so Play Services permissions to run in the background and unrestricted will matter a lot more.