I have noticed throughout the use of my phone that when typing sometimes the haptic feed back just stops working. Or it will cut in and out. This happens with or without a case. I've done a factory reset and it doesn't seem to help.
I was literally in mid-text yesterday when the haptic feedback got significantly weaker. It isn't just the keyboard either. The four keys at the bottom are affected, too. The vibrations are just weaker altogether. And for someone who constantly leaves their phone on vibrate, this poses as a serious problem. I've tried turning the setting on and off and restarting the phone. And from what I've read, a factory reset won't do the trick. Have you found a solution yet? Any knowledge gained would be much appreciated.