Call icon and Video call icon is showing on all app background

[Madhan26]

Call icon and video call icons showing on Background in all apps 

Seems like someone monitoring this device 

When I try to take screen shot it's not visible on Screenshot 

Anybody know what is that ????

[Madhan26]

What that's the reason ?

[Pappu2020]

because you use long time call and video call for long period.