In Settings go to Focus.
At the top you should see "Do Not Disturb". Click the arrow to the right on that line.
On the "Do Not Disturb" window scroll down to "Set A schedule".
Here you will see the current Schedule/s, eg, 2200-0700. Click the arrow to the right on that line.
On the Time page you will see 'Schedule" at the top with a button to it's right, turn that off. That's it!
PS. Schedules set in Focus will effect all devices logged into the same Apple account if you have "Share Across Devices" turned on, so as you mention your iPad, that is normal behavior, it will also effect your computer/s and watch if you have one.
You can turn "Share Across Devices" and "Focus Status" off on the first Focus page in settings but if you have no schedules it's not really necessary.