Samsung Galaxy Note 3 — Slow keys when typing ?

I have a standard unmolested note 3 n9005 (i think) in the UK on EE. The last week or so the keys pressed when typing often slow down and i find myself 2, 3, & sometimes more presses in front than whats shown on the screen. When this happens i am not getting the vibration from these keys either. I have to spell very sloooooooowly and wait till each character apperars on screen before the next one is pressed. Typing this its all working ok but sometimes it doesnt. Got rid of as much as possible in the background, ram etc also. Any help would be appreciated.

Thanks