Work in Chrome, not work: Firefox, Edge

I don’t have any idea for now.

The fatal error is not related to my problem? The scripts.js:146 also contains ‘https://’ string. Maybe that?
If you send me a debugging script to your code, I insert it whenever you want.

Which scripts.js do you mean? In the theme?

Yes. In your plugin. I searched for https:// in you plugin, and there are some.
But today, I found a not https page, where the same things happened.

No hard-coded URL value exists in contact-form-7/includes/js/scripts.js.

I have found already 6 sites where cf7 forms not working with Firefox!

No one else have the same symptom? I am and @fra2017 the only two person who has this problem?

Please help!

I updated my Contact form to 7.4.8.1, but it’s still the same problem.