Keypad glitches iPhone 6s

SO my 6s keypad is suddenly weird- unlike some of the other posts, I've seen with people discussing keypad weirdness... my phone sort of buzzes & the keypad "blinks" a lot, and blocks me from entering text characters. It's a royal pain.

Any suggestions? I've already done a "hard" shut down & reboot (holding both buttons until screen goes 100% dark, then rebooted the phone) and that accomplished pretty much nothing.

Thanks!