Elementor Form Shows red cross “x”

I’ve set Mailpoet 3 plugin and fields according to instructions. Everything works fine, I get emails from that form, I get subscriber in the mailpoet list however Elementor form shows this red cross whenever it is submitted.

I made sure that

1. Mailpoet 3 plugin + premium is installed correctly
2- Action after submit in Elementor forms are correct
3- Field mapping for Elementor form and Mailpoet 3 tab are correct

Results: I recieve email from “Email, Email2” and subscibrer in the list from Mailpoet3

Screenshto: https://drive.google.com/open?id=1_otV7x3p5BscErOe6E9bgOAkj2jDCKku

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