1

I noticed recently, that when i answer a phone the phone (running stock 7.1.2) the "Do Not Disturb" mode gets triggered. I'm not 100% sure it's coming from the app so i figured i'd mention it. This is the app i'm using to manage DND

Play store: Do Not Disturb (pro) by Cabooze Software

My set times are

Weekday nights from 10pm to 7 am
weekend nights (fri-sat, sat-sun) from 11pm to 8am

It happened just now again when answering a call at 5.15pm which is outsite of the DND frame.

2

There are a lot of third-party apps in the market, please ask the developer of that app you mentioned for helps. We don't know that app.

3

The app seems unrelated. If i untap "DND" prior to answering the call the recorder states "cannot record call"