Why cant I answer my zte avid trio without backing out to home screen

[Android Central Question]

I have to hit back button to home screen. Then when I push the phone icon, it says return to call in progress then I can answer after I swipe the center button to the answer icon.

 

[B. Diddy]

Welcome to Android Central! When you get a call while you're using another app, do you not get a notification at the top of the screen that you have an incoming call?