Redirect does not work

Hi there,

I have a question which is driving my crazy for hours already. Maybe someone can help, I would be very grateful.

I integrated the Contact Form here: https://www.abtipper.de/bestellformular/

Everything works fine. You can send the form, get the confirmation message and I receive the respective mail.

But once I included any further option on_sent_ok (e.g. Google Analytics or Redirect), the problems start. Whenever I include a on_sent_ok, neither the original confirmation is shown nor the action I would like to see (e.g. Redirect) is completed.

Does anybody have a solution how I could run this.