Image resizing

Hello, I am working on https://dev.clmauctions.com and have installed this plugin on the home page. It works great except that between the screen size of 500px and 1200px, the image shrinks down to 69px high and shows 4 images across. This is not what I want and it seems like a bug. Could you please take a look and let me know how to fix this?

https://www.ads-software.com/plugins/slider-responsive-slideshow/