Portfolio links not working – OMNI theme

site = https://dexterford.co.uk/rmi

I have set up a portfolio in the CASE STUDY section of my page, each item should have a green box on rollover, that shows a link to the portfolio item.

Check out the PORTFOLIO section here to see how it should work https://themeforest.net/item/omni-responsive-one-multi-page-html5-parallax/full_screen_preview/5082172

I have tried the theme creator’s support forum over at Themeshifters, but they aren’t the fastest at responding, so I’m hoping someone here is generous enough to propose a solution.

thanks.