All of my background apps get killed when I turn off the screen. This is particularly annoying for my most-used messaging app, WhatsApp.
And yet, it gets killed in the same manner as battery optimization would. If I look at running background processes:
When I then press the power button, and power it back on after < 10s, the list is the same. But if I wait longer than that:
...whatsapp has disappeared.
This happens for all apps I install that have some sort of useful background feature - the Battery Optimization setting doesn't seem to do its job anymore.
What else can I try to diagnose this?
NB0: Android 7.0 on DOOGEE S60
NB1: This just started happening some time ago, i.e., it did work propertly when I got the phone.
NB2: I know how to use
NB3: I'm also fond of trying new apps and have ~400 apps installed. Ideally, I don't uninstall/disable all of them 1-by-1 to see which one is the culprit...