Stock 5.1.1 killing apps that should be persistent

Updated to stock 5.1.1 on my note 4 n910u variant last week, and I noticed that it kills apps that are suppose to stay in memory,like Adguard or pintasking. This was not an issue on 5.0.1 and I'd like to know if anyone has observed this.

I'm not running any task killing apps or Xposed modules.

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System killing apps in background

Hello guys! When I run a application such as a DLNA server, torrent and lock the device after a while these applications are switched off. When the screen is turned on, everything is okay. I do not know what is the cause, it started like this happen recently. Anyone know what is going on and how to fix it? I'm on rooted stock P605XXUDOE2.