How do you get rid of the green bar on the top of your phone when you are in a call, but another app

[TranquilTide13]

the green bar also shows the call duration, Whenever I get on Instagram or try to get on another app, it always stay on the top, so if there is something on the of the screen I have to press, I'm not able to click it otherwise it takes me back to the call, I have a ZTE Blade X Max, And I have been struggling with this issue for quite a while, I know that the bar is removable, because on my last phone, the ZTE Grand X Max 2, everyone said you weren't able to get rid of it, but I was able to. All help is appreciated, thank you. if anyone knows how to get rid of it please tell me, I have had this problem for such a long time

 

[Sam_Gs7]

@TranquilTide13: I know what you're talking about it happens
to Me in my Sam_Gs7 : Usually when the receiver of my

call "Hang up first" instead of myself - Then that green
Bar appears on top of phone screen. The bar in

my SGs7 show the phone icon in red, so if
I tap on it disappear & take back to

Home screen..Sorry can provide
a fix just commenting