There were a couple of similar posts of the exact same slider issues that it appears I am having the same results, but the solution suggested is not working for me.
Problem: The second slider on project called Ball (Wine Slider) works great up until smallest mobile size (portrait) causing the other slides disappear. They are still there, just far below the target area. the first slide works correctly. Even with divs installed in each one, the only solution is to move each slide near the mask for it to appear. All other sizes of the project look fine, it is only on this last, small mobile size.
I tried to find the problem, but your classes are sooooo messy that it’s very difficult trying to find anything. You are using empty divs inside your slides, setting different hight, paddings and margins on every slide and overlapping everything at each breakpoint.
I think if you do some cleanup the problem will be solved by itself. If not, them you can post the cleaned version here and we can take a look.
If you aren’t sure how to clean things up, I recommend you watch the Webflow University videos: