Filter in Featured Photos

Hi,
I have used this code (below) to remove the darkish filter on the featured photos, but since I change the plugin on the main page (from WP resent news to Recent Posts Widget With Thumbnails) the filter came back. The code is still there and when I modify it on Customize I can see the changes. BUT the changes arent visible on the website.

What should I do?

This is the code I have been using (and which is still written on the Additional CSS:
.overlay { background-color: rgba(0,0,0,0.05); }

Thanks!

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