Kirby sessions not working in Iframe on Safari

I’m working on a project which i have to run into an iframe on an other domain (Wordpress site). It all works fine except that the Kirby sessions are not working. And this only on Safari.

I have tried this workaround. (
This works with PHP Sessions ($_SESSION["favcolor"] = "green";),

but when i use kirby sessions it doesn’t work.
$session = kirby()->session();

Any one an idea how i can fix this?

PS. I have a kirby licence for the kirby part :slight_smile: