Xamarin.Forms not working properly on some android devices.

I'm creating xamarin.forms app. I've written a background service in android project which runs after every two minutes (with the help of broadcast receiver).
And I'm calling that service from portable project using dependency service.
This app runs correctly on some phones, but fails on some phones at the point where that background service is getting called.
Can anyone please help me finding the solution to this strange problem ???

Thanks in advance