Random Haptic Feedback

[jesj]

My Lumia 730 is giving random haptic feedback. This is the second time in two weeks. The first time was two days after I got this device and the other today.

During this event the screen remains unresponsive and toggles between open app windows on its own. On both the occasions I have had to power down the device after which the device functions normally.

Please advise on what could be wrong and what should be done to rectify this issue.

Thanks in advance!