Hi Anna, i just ran into a similar issue with dynamic content.
On my Event’s detail page. There is a problem regarding the dynamic slider.
I have 5 possible slides. All conditionally visual. This works perfectly, However the slider ALWAYS thinks that there is one last slide. For now i solved it by giving the mask a nice background so its not just plain grey. However It would be nice if it could understand that theres not extra slide.
Did i make a stupid mistake again?
I found this guy having the same problem but no solution 
I've created a Dynamic slider but there is a weird problem - General - Forum | Webflow