On the master page, i have a header and sticky footer Is checked, i have a page with a lot of content and the footer showing, on another page I have only a slideshow.
Not sure if I understand your question. It seems to be incomplete. I understand: The long page shows the footer, the short page …
Perhaps this helps:
You can override the „Sticky Footer“ option of your master page, if you change it in „Page Properties“ of a layout page. You also can override the minimal page height of your master page by changing it on your layout page.
Best practice is, to choose a very short page height on master. The height will grow dynamically it you – for example – add (non footer) elements on your layout page near the footer area and/or drag an element downwards to the footer area.
If this doesn’t help, please give us more informations (screenshot, link, .muse file).
I checked again on the master page, and it turns out that in one of the broken points, the footer moved down under the page, I do not understand how it happened , i fixed it, thank you anyway
Page height and „Sticky Foooter“ can be changed breakpoint-wise.