On my S10+, the Do Not Disturb option used to follow the schedule setting. However, after the Android 10 update, it now still turns on as scheduled, but fails to turn off as scheduled. I am now forced to manually remember to turn it off when I wake up. I attempted to delete the schedule and create a new one to replace it, but same issue exists.
Have you tried wiping the cache partition on the device?
Been experiencing this lately on my Note 10+. It turns on as scheduled but doesn't turn off accordingly. I have to manually turn it off. I'm not sure if it started because I'm wearing a galaxy fit watch that syncs the DND option of my phone. DND used to work smoothly and I can't find the fix. Does anyone have the solution?