responsive columns/header option on medium screen

Hi,

I try to use the parameters for responsive columns/header option (especially for font size), i specify the font height in px in the header of my column for small and medium screen, that work fine on mobile device but not on medium screen in low resolution (near 700-900px), the font size keep original size and go out the column box, do you have an idea why it’s didn’t work for me ?

Thank’s for your reply

Best regards