Hello,
I've installed some messaging apps through Google Play Store and I've noticed that on GrapheneOS, notifications are extremely delayed (even an hour late) and I even completely miss calls because they don't show up. On other Android devices with the same apps there is no problem at all.
I've already enabled unrestricted battery usage for both Google Play Services and the apps in question, but the situation is still the same. I can't think of any other possible cause other than my VPN DNS server doing too aggressive blocking (I have unblocked several Google domains for Play Store to work in the past).
If anyone knows of any other possible causes for this problem I can troubleshoot and/or can provide a list of domains FCM needs to work so I can check that they aren't blocked, that would be very helpful.
Thanks in advance.