Restored from backup?
Try restoring as a new device, not from a backup, and do not sign into your Apple ID during Setup Assistant.
If the problem persists, it's a hardware issue.
If it disappears, it's a software issue, probably with corrupted data of some sort. You'd have to restore from an earlier backup to see if the problem goes away.
If it's a hardware issue, then your options are:
1. If it is still under warranty (one year from date of purchase, or two years if you have AppleCare), then it should be fixed for free by Apple. They're going to want to do their own troubleshooting, FYI.
2. If it is not still under warranty, then you're looking at about $149 for an out-of-warranty service.