Title just for hover (image carousel) not working

I just want the title text to show on hover, so in order to achieve this I have set the text to transparent, and then set it to white on hover. It works on the divi builder, but then on the live page it just looks transparent on and off hover, rather than showing as white on hover.

I saw someone else had this issue a couple of years ago, but there was no fix on the thread.

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