Hi Nick,
Bit hard to tell what’s going on – looks like there might be some conflicting CSS somewhere.
I see you have a child theme with custom CSS, and that you’re importing CSS from another theme. I’m guessing there’s some CSS in one of those files that is causing some kind of conflict.
It’s hard to tell without combing through all of the code, so maybe just try commenting out chunks one at a time to test and see if you can find the problem code.
Let me know 🙂