I just ran into this issue on my Verizon LG V10. When minimized, phone calls would appear in the 2nd screen so I can hang up from the 2nd screen and look at other apps while on the call. However, now I get this annoying call widget that I cannot get rid of.
I could not find the settings mentioned earlier on the thread:
Settings > Networks Tab > Call > Show Voice Calls While in an App > Second Screen.
Any help on how to get my calls back onto the 2nd screen?