First post here. I just moved my website (Dvir Barkay Photography) to editor X with the hopes that the dynamic resizing of elements to fit the viewport size would enable me to put a slideshow on my main page that changes to exactly fit whichever viewport the website is viewed on. For some reason, the slideshow looks fine on larger screens but the second you try to view it on a smaller laptop the image isn't scaled down to fit the viewport height and so you have to scroll down to view the full image. Whether I set the size to 100vh or 100% doesn't matter, I get the same result in the end. Would love some help with this!

Thank you, I am glad you enjoy them!
Nice photos, btw!
Is the gallery stretched, or have you set the sizing directly?
I tried replicating your problem, and it seemed to work ok with the (unstretched) settings shown below.
FYI, here's my test page (note that the Editor X header causes some scrolling on ALL viewport sizes -- I didn't take the time to adjust for that header): https://laborstreet.editorx.io/xpractice/gallery