I started having the same issue with my 6s plus. Tried 2 replacements. First time it was freezing. Second time it was freezing and the digitiser was hyper-sensitive. It would randomly click on its own.. Finally third time the digitise issue went away, but freezing continued - albeit less frequently. After a week of usage, the frequency if freezing seems to be reducing - in fact didn't freeze in last 2 days - touch wood... While iFixit customer service was good, I think the screen and digitizer quality is definitely an issue. I wish I had it replaced by Apple Genius bar.