White background overaly

When the page loads the hero banner renders fine but then there is a white background overlay when the page has fully loaded. Any ideas as to why this is happening?

https://www.wepc.com/tag/prebuilt-desktops/
https://www.wepc.com/tag/laptops/
https://www.wepc.com/tag/peripherals/

It appears to be isolated to taxonomy pages

We have AdThrive installed which might be affecting it.

The page I need help with: [log in to see the link]