error in safari when sending popbox via elementor

I can provide the concerning link only private since it’s a page for condoleances.

The problem is that in a Safari browser (iphone and mac), when someone wants to send the form in the popup box, it only says Error.

In all other browsers the form is being send without any problems!
Can’t find this problem anywhere in Google or on this forum, but hope you recognize it and have a solution for it.