Plugin only visible when logged in

While on the test-site the plugin worked without an issue, now moving it to the main domain now I can only see it when I am logged in to the page. If logged out, on various browsers and in incognito mode, it doesn’t show. I tried it also with the 2021 theme deactivated all other plugins but it’s still the same issue.

The test-environment is on a different webhost and it worked without a problem there (logged in AND logged out) – I would appreciate a pointer as to what can cause this issue ??

Thanks a lot!
Monika

The page I need help with: [log in to see the link]