Slide In activated - no link / button is clickable

Dear Team,

I see a strange bug.

When Plugin is installed and I select EN version (with WPML translated) of the website, I can click no button and no link at all and the slide does not appear. (only happens when you are logged out)
http://www.mercure-hotel-kamen.de/en/

I modified blugin with css to don´t show the close button.

Could you please check and let me know?

I have newest version of all plugins and theme

Thanks
BR
Stefan