If Do Not Disturb keeps turning itself back on, a Focus schedule, Smart Activation, or another automation is usually more important to check than simply switching the Focus off again.
Turn Off Do Not Disturb Now
Open Control Center, tap Focus, and tap Do Not Disturb if it is active.
Check Do Not Disturb Schedules
Open Settings > Focus > Do Not Disturb and review every schedule or automatic activation listed there. Disable or edit any rule you do not want.
Review Smart or Contextual Activation
If the iPhone offers automatic activation based on context, review that option. Also inspect Sleep, Driving, Work, and other Focus modes if you are unsure which Focus is appearing.
Check Focus Sharing and Devices
Focus status and behavior can interact with your other Apple devices when sharing is enabled. Review the Focus settings on devices signed in to your account if the behavior seems to return unexpectedly.
Check Shortcuts Automations Too
If the Focus settings themselves look correct, review personal automations in Shortcuts that may change Focus modes based on time, location, app activity, or another trigger. Disable only the automation responsible for the unwanted behavior.
Frequently Asked Questions
Why does Do Not Disturb return after I turn it off?
A schedule or automation may be enabling it again.
Where are the settings now?
Settings > Focus > Do Not Disturb.
Should I delete the Focus?
Usually no; removing or changing the unwanted schedule is enough.
Summary
Turn Do Not Disturb off in Control Center, then inspect its schedules and automatic activation under Settings > Focus if it keeps returning.
Matthew Roberts created this site to help his friends and family with questions that they might have about how to change the settings on their iPhones. It now serves as an archive of iPhone how-to guides to help anyone that stumbles upon this website.