Important: Enable "Wake Lock screen for notifications", and "autostart" for desired apps first to ensure proper notification functionality. I also recommend disabling "MIUI battery optimization".|
I have found a temporary fix for delayed or muted notifications in MIUI 11.
Go to settings • Passwords & security • Privacy • Special app access • Battery optimization • Tap the arrow next to the blue banner which says "Not optimized" • Select "All apps" • find "Notifications", tap it and select "Don't optimize". Do the same thing for "com.android.smspush".
In my testing I found that this reduces delays from minutes to 10 seconds or eliminates them completely. Furthermore, Google Keep Reminders are no longer silent and able to push notifications.
If this doesn't work for you please ensure that you have notifications for desired app or apps enabled. MIUI often sets notifications to low priority.
Unfortunately "com.android.smspush" resets back to "optimized" by MIUI after a restart. This seems to cause most of the delays. It could be resolved easily if it wasn't for MIUI's aggressive behaviour.
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