Android
Optimize Battery Usage for Background Apps auf Android
Android manages background activity per app to extend battery life. When an app is marked as optimized, the system can pause its background processes, delay network access, or stop sync jobs shortly after you leave the app.
This affects messaging apps, mail clients, and fitness trackers the most, since they rely on constant background connections. If notifications arrive late or not at all, checking this setting is usually the first step before assuming an app is broken.
To change the behavior for a specific app, open Settings ➔ Apps & notifications ➔ Advanced ➔ Special app access ➔ Battery optimization. By default the list shows apps that are already set to Not optimized.
Tap All apps to see every installed app, then select the one causing trouble. Choose between Optimize and Don't optimize.
Setting an app to Don't optimize keeps its background processes running normally, which fixes delayed alerts but increases battery drain. Reserve this for apps you rely on daily, not for every app on the phone.