Issue: Strange behaviour in auto drop downs

So on my auto-fill drop downs nothing appears until I click in the box:



After that the drop down appears, but then my cursor is stick as the hand icon.

I can't replicate this on the demo Xf Wiki. Same for both mobile and desktop Chrome.

Same for both the search function and finding Categories (which is where it is causing me trouble at the moment.)

Any ideas where this could be?

Tried default Xenforo theme so it rules out customisations to styling at least.