HB Image Box with sidebar not responsive

Hello,
I have three hb-image-boxes to the left of a right sidebar. They do not behave responsively: the image width gets compressed. If I remove the sidebar from the page the images scale correctly. The same occurs with your demo page for the hb-image-box feature. Is there a fix for this?

I have tried the custom CSS code offered to another forum member:
.custom-hb-box img { height: auto !important; }
This generates a black bar at the base of each image and doesn’t resolve the scaling issue.

Appreciate your help,
Andy.

2 files attached