Home page Slider doesn't slide

Hello!

I am very satisfied with this theme! In my opinion, it is the the best theme in terms of customization.

My problem is that no matter what settings i apply in appearance>customize the slider only shows the first page; it doesn’t autoplay, nor changes slide when clicking on the arrows.

My website is wwww[.]mdlab[.]mech[.]ntua[.]gr .Currently a maintenance page appears because of this problem, but i could possibly provide anyone willing to help with contributor credentials in order to view what is behind.

Thanks in advance!