Randomly vibrating - iOs 15 - iPhone 13Pro

My iPhone randomly vibrates for no reason - all of the time. When it is closed or when I am using it. I have turned vibrate off and back on, checked notification settings for apps, restarted my phone, etc - all to no avail. At times it vibrates every few seconds as if I am getting a notification, although there are zero notifications.

I cannot figure out how to fix this problem.