Galaxy S6 :: Letters At The Beginning Of Words Disappearing Whilst Typing

Since the last update (August 2015), whenever I type some letters letters (one, sometimes 2) from the beginning of the word disappear before I can finish typing the word. This causes autocomplete to think I'm typing a completely different word.

E.g., I tried to type "think" - the "t" disappeared by the time I had gotten to the "i"(despite it initially appearing initially), making the phone think that the word is starting with "h", and leading to issues when I press space (despite typing think perfectly, the phone autocorrected to the nearest matching word starting with H as "h" was now the beginning letter)

This has only been an issue since updating my phone this week. I thought it might have been the swipe function messing up, but turning that off, it's still causing me issues when I type normally.