How to fix VPN automatically closed by phone in the background?

[sevbalason]

Okay, here's the situation. I have a Vivo V5 lite phone and I'm a VPN and http injector user. However, whenever I'm using a VPN app or the http injector, the phone closes these apps, wich results to disconnection, when left in the background for long. Can anybody help me how to stop this from happening? Thanks.

 

[A Bochur]

go into settings>data usage and see that those apps are not restricted for background use