Dear @felixk
Some first steps of debugging if you will:
Wordpress, Lay Theme & Laytheme's Addons are all up to date ?
Any Custom CSS or JS that may interfere is temporarily removed.
Any third-party plugins de-activated to see if this resolves the issue.
If your WordPress Dashboard shows a warning "PHP Update required"
please update your PHP version in your webhost control panel.
Additionally please take a look at https://laytheme.com/troubleshooting.html for known problems.
If these do not help:
Could you please send your website address, /wp-admin/ username and password and a link to this topic to info@laytheme.com?
Sincerely
Richard