

Most apps typically use Google services for notifications, so all apps use one single service running all the time.
Without Google, apps can develop a fallback where each app polls for its own notifications, but continously running a service per app costs battery, so the services do not run all the time. This is the reason why notifications are delayed.






No, but they see that you are connected to a tor entry node and that someone is sending you data. From this they can conclude that you are running a tor proxy.