QA Issue - Slider jump to the next page, instead of sliding

[ghost]

This error can be reproduced in: Safari (desktop).

Steps to reproduce:

1. Open https://www.devtreff.io/ in Safari
2. Scroll down to the slider.
3. Click on the slider arrow.
4. See that the slider jumps to the next page instead of sliding.

Expected result:
After clicking on the arrow new slider page should slide in.