Wordpress theme Flatsome 3.11: UX Builder not loading


Staff member
I've just installed Flatsome theme version 3.11.0, wordpress 5.4, php 7.4, mysql 8.0 on my SSL protected site.

I disable all plugins, not even one.
First, I can edit home page easily. But when I edit other page, like contact, about... it was not loaded.
I checked console, has a error in image 1.

Uncaught TypeError: Cannot read property 'isRoot' of undefined
    at t.value (editor.js?ver=3.11.0:2)

But I refreshed page while console opened, no error display in image 2.
That error only show when console closed.

Please help me, thank you so much.

<a href=" " rel="nofollow noreferrer"><img src=" " alt="error displayed when open console after load page"></a>
<a href=" " rel="nofollow noreferrer"><img src=" " alt="error not display when open console before load page"></a>