Notifications don't work w/ locked screen

BewareTheGlowies

Device & Setup:

GrapheneOS with Sandboxed Google Play
Issue: Push notifications completely stop arriving after screen has been locked for approximately 10 minutes

Current Sandboxed Google Play Configuration:

Play Store: Notifications, Network, Sensors| Battery: Optimized
Google Play Services: Network, Sensors | Battery: Unrestricted
GmsCompat: Notifications , Sensors | Battery: Unrestricted

The Problem:

When I receive a notification (like a WhatsApp message) while the screen has been locked for more than ₁₀ minutes, nothing appears until I manually unlock the device. Interestingly, notifications work perfectly for about 5-10 minutes immediately after locking the screen, then completely stop.

Troubleshooting Steps Already Attempted:

Set unrestricted battery optimization for all affected apps
Changed Play Store battery setting to unrestricted
Enabled notifications permission for Google Play Services
Disabled "Suspend execution for cached apps" in Developer Options
Disabled Private DNS
Disable eSIM support (and thus only using the physical SIM)
Factory reset
Fresh GrapheneOS installation

Current Status:

Still experiencing the same issue after all troubleshooting attempts. The pattern is consistent - notifications work briefly after screen lock, then stop completely until manual unlock.

Has anyone encountered this specific timing-based notification issue? Any additional settings or configurations I might have missed? I'm particularly curious if this could be related to GrapheneOS's security features or if there are other Sandboxed Google Play settings worth investigating.

Any insights would be greatly appreciated!

mmobder

BewareTheGlowies
have you thoroughly described all connection -related aspects of yor environment? vpns, android-wide setting re data saving, etc?
I have somewhat complicated setup (though relying on unifiedpush and not fcm) and I don't observe such a behavior.

BewareTheGlowies

I think I've solved it by clearing the GmsCompat data + reinstalling problematic apps. I'll follow up if issues persist.

de0u

BewareTheGlowies I think I've solved it by clearing the GmsCompat data + reinstalling problematic apps.

Thanks for the report!

BewareTheGlowies I'll follow up if issues persist.

It would also be valuable to report again if it says fixed.

BewareTheGlowies

de0u

Unfortunately, the issue persists. After leaving the phone idle for a few hours and sending messages to trigger notifications at random times, the issue began appearing in strange patterns: First, notifications were only showing when I tapped the screen or pressed the side button without needing to unlock the device. After a few tests and reboots, notifications were only appearing when unlocking the phone, or not showing at all until I opened the app.

I tried changing every listed app (system apps included) to unrestricted battery usage, along with several other adjustments. Ultimately, I fed GmsCompat and Google Play Services logs to an AI, and it appears there are some interesting issues with GmsCompat. However, since I'm neither a GrapheneOS nor Android developer, I can't determine whether those errors in the log are expected or unexpected. Some were related to SELinux and other things I don't remember, because I concluded that something must be in a broken or unfixable state and deleted the conversation.

de0u

BewareTheGlowies Is the situation the same if Wi-Fi is disabled to force the device onto mobile data?

BewareTheGlowies

de0u

Sorry for not commenting on this, I'm not using WiFi at all.

BewareTheGlowies

mmobder

My setup is very basic. GrapheneOS with only 3 or 4 apps installed, and only 2 of them use push notifications (banking app and WhatsApp). 2 mobile lines (physical SIM + eSIM), and I use the Lawnchair launcher. I don't use a VPN or anything fancy.

The rest of the system tweaks I've made are I think irrelevant: dark mode enabled, font size adjusted, camera, microphone, and location turned off...

At first, I wasn’t using Google Play Services and had no intention of doing so. However, after comparing battery usage between WhatsApp's own system for receiving messages and push notifications via FCM, I found that FCM push notifications use significantly less battery. (It’s also worth noting that the banking app requires FCM anyway.)

I read about Unifiedpush before installing Google Play Services but there are few apps that support Unifiedpush.

de0u

BewareTheGlowies At first, I wasn’t using Google Play Services and had no intention of doing so.

Some apps decide whether or not it's possible to use Google's notification system the first time they run. So it is necessary to install Play before installing apps that use it. After the device was reset and configured again, did the Play installation happen before the apps?

BewareTheGlowies

de0u

Yes, but for the first time I wasn't aware of that. The funny thing is that the notifications were working well initially. After several days without problems, I started noticing issues with notifications, and that's when I began troubleshooting. First by uninstalling apps and Play Services, reinstalling them, then eventually doing a factory reset and so on.

The weird thing is now I have one app working while phone is locked while the other still requires to unlock.

BewareTheGlowies

Notifications seem to work consistently for WhatsApp, but for banking app, notifications work with heavy delays and I can't ensure they work consistently after another (the latest) fresh install of the latest build for Pixel 6a. This makes me think that maybe something with FCM servers is wrong, or maybe Google is being evil with GOS users the same way they are with Invidious (alternative YouTube frontend).