How do you lock the screen when talking?

[jwmoss]

I have had my Note 4 for a long time now. I've only recently started having a problem when I talk on the phone - I think my grandson changed a setting while playing on it or something, but now when I talk on the phone it starts opening new screens and changing my settings and such. How do I lock the screen while talking on the phone?
Thanks,
Janna

 

[Podivin]

I suspect your proximity sensor is covered with something (dirt, gunk and/or part of the phone cover). To my knowledge there is no way to turn on/off the proximity sensor.