Horizontal Gallery Image Size does not change on mobile

Hello,
I have a horizontal gallery that should be displayed differently on mobile than on desktop. So I have set 2 and show and hide them accordingly. that works so far, but the change of the image size and the height of the gallery are not taken over, no matter what I do. If I change the images in general, the new images are also displayed, but also in the wrong size. What am I doing wrong?

Settings:

I have also tested image size large 1030 x 1030, but it didn’t work either (on the desktop, but not mobile).

thanks in advance

best KiM