Hello,

I see you have a bilingual site. What translation plugin are you using? From what i see from inspect element, the mobile menu does not have any items in it. That’s why it does not open.
You may need to translate the menu as well. Some translation plugins do not display a page/post/feature unless it has been translated first.
Please check and let us know how it will go.

Best regards!

Hello,

Please fill in the necessary information on your extra information fields of your profile data. So we can give it a closer look.

Read this article for more information.

Best regards!

Hello,

The issue happens only when the child theme is activated. I switched to parent theme and the mobile menu has no issue.
Please try removing functions.php file from your child theme and try again.
let us know.

Best regards!