Modal not Showing on safari

Hi everyone,

I’ve created a landing page where a form pops up after button click, using some custom jQuery.

The form is based on this template by Flowbase and uses the slider element for the individual steps:

Everything works fine on Chrome and FireFox, but for some reason the form content doesn’t show on mobile safari browsers.

Can anyone give a hint on why this might happen?

Here is a screenshot of how it looks like on safari mobile browser:

vs how it should look like:

Here is my public share link: LINK