I have a Moto G7...same issue/problem & I just figured out that the phone automatically goes in to DND mode when I put the phone screen side down (flat). I've tried looking for 'FLIP FOR DO NOT DISTURB' in the 'Moto app'. Does not exist. Don't know WTF these previous poster are finding that??? Spoke to a 'robot' at Motorola. No solution found. It appears to just be 'built in' without an option to turn it off. Like the original poster, I'm more concerned that if my phone gets into a flat position inside my pocket, I won't hear important/expected phone calls. I may just call Motorola to see if they know anything....most likely they don't....just like every other mega company. Everybody know NOTHING!@#$
UPDATE: Just spoke with a live, real person at Motorola (always someone from the Philippines). It appears I was going to the WRONG 'Moto' section. The correct 'Moto' is the 'Moto ICON' on your apps page that has all the app icons on it. Once you are there, click on the THREE BARS next to, 'Hello Owner'. There you'll find the 'Moto Actions' & the source of the issue....I found the 'FLIP FOR DND' clicked ON. Problem solved. Who knew. And that sucker was BURIED DEEP!@#$ HTF that got turned on automatically I'll never know. ARGH! Lastly, my husband is IT DIRECTOR of a large company. HE couldn't even find it!