Why is vibrate continuing after I either made or answered all calls?

After I've either been making a call or answering a call, from the start of the call to the finish of the call, unless I click my lock button on the side of my phone once or twice in order to stop it, the phone is staying stuck continuously vibrating for the whole entire duration of the phone call no matter what app I'm using to call from?!?!?

• Any suggestions for a solution?!?
• Please and thank you!!!