Clearfix issue- portfolio images not appearing

Hi there, I have the Garnish theme, and I made modifications to personalize my website. Everything was working fine until I updated my wordpress version (that’s the only change I made, so I only assume that’s the cause). Now, when I click on the thumbnail to my portfolio, the text shows, and the slider to click through the images, but the images don’t actually show up. When I inspected the element, I found that if I changed the position of the images to relative, they showed up… but upon deeper investigation, I found that – in my “slides container clearfix” – if I uncheck the ‘overflow: hidden’ box, the images reappear, but the slider itself is still stuck at the top, instead of moving down below the images. I don’t really understand clearfix, but I am trying to figure this out! It seems as if the clearfix is not working correctly??? Any advice would be helpful!!