how do you turn off Do Not Disturb?

If you do not use all of the various DND scenarios and simply have DND turned on, you can turn it off in the Control Center by tapping on the moon icon in the Focus box.

I frequently use the basic DND, and I turn it on and off as needed in the control center.

Turn off all focus (DND, Driving, Work, Sleep, Personal, Any other). Open the Control center and see if this helps.