Slider problem with other screen resolution

Hi! I am using free modality, and it is fantastic, but… Everything is ok with full screen resolution (height of the slider is 550px, images too, and there is no gap), but when I am going to see website on my laptop (with other resolution) then the white gap mysteriously shows up between slider and footer (I have no other content on front page). I tried everything I know, but it looks like something is wrong…Is there any solution for this?

Thank you in advance!