Mobile Phone Portrait Columns

This is a TERRIFIC plugin – very happy to have found it!

I am though seeing an issue where I have 3 columns on desktop layout which I want – but when changing the settings to show 1 column on phone portrait, it doesn’t work. It still shows the 3 columns across. Seems landscape settings work, but not not portrait.

Any way to override this and get it to stack 1 column images on mobile portrait?

Thanks!