Need Help With iPhone Ringing Sporadically

[calkemper]

Need help with inconsistent ringing of my iPhone 6 Plus. Driving me crazy. Sometimes it rings & regularly doesn't. Missing important calls. It happens on Lock Screen & while phone is "on." Any advice greatly appreciated. Cal

 

[C DM]

Do you have Do Not Disturb enabled (perhaps on a schedule)?

 

[calkemper]

Do you have Do Not Disturb enabled (perhaps on a schedule)?

I'll check it out. Thanks!
[doublepost=1461973905][/doublepost]Do the Do Not Disturb function WAS turned on . . How???