This is the solution to the above problem. I went through hell to find it. I will keep it simple and straight to the point.

Nb: This is for those people that are using phones that has "Clean master app" on it. E.g innjoo halo plus, etc

Step 1: Go to "clean master" app on your phone menu then tap on "Tools", in the tools page tap on "auto boost"

Step 2: in the "auto boost" page on the upper right corner you will see a menu that looks like 3 vertical dots(...) Tap on it, click on settings.

Step 3: a page will appear, on that window tap on auto boost mode to disable it. It will switch the autoboost off.

Then you are good to go. No more annoying auto closure of running application , especially downloads and audio streaming.

Many people need to see this, especially if you just got yourself a new China smartphone