Random vibrations?

T-Mobile Galaxy S7 here. There are times when I'm using the phone and it suddenly vibrates, as if receiving a notification. The thing is, there is no notification being received. I've already checked the most probable causes: Notification Reminder in Accessibility and Smart Alert under Advanced Features. Both are off. I'm at a loss and the random vibrations get annoying.

Sent from my SM-G930T using Tapatalk

from xda-developers http://ift.tt/1rJe2sd
via IFTTT