don’t see the slider

I noticed that I cannot see anymore my pictures of my slider on my website https://agoshop.at/algenentferner/ only the points.
I use the slider SLAVA YURTHEV.
Here my code:

<p>{{widget type="SYSliderBlockWidget" ids="3,5,7,9,11,13,15,17,19,21"}}</p>

Also I noticed is, that I cannot acitvate the Page Cache and WeltPixel GoogleTagManager Categories Cache. But I don’t know if this has a connection with the slider.

Hope someone can help me there.
kindly regards