Using wp_editor tinyMCE in metabox cause form alert on leaving page

Question

Using tinyMCE as wp_editor in a custom post type metabox create an alert when I try to submit or If I want to change location

I don't have such behavior using Quicktags, but since TinyMCE is easier to use I'd like to use it.

I'm aware that using tinymce in a metabox can cause problem since it can't be move inside the dom, but it's not the problem here. I also used the recommended hooks in wordpress codex , ‘edit_page_form’, ‘edit_form_advanced’ and ‘dbx_post_sidebar’ but It doesn't solve my problems

https://developer.wordpress.org/reference/functions/wp_editor/

Answer 1

This is a bug in WP core 5.6.1:

https://core.trac.wordpress.org/ticket/52440

which will hopefully be fixed by this:

https://core.trac.wordpress.org/changeset/50366