Using wp_editor tinyMCE in metabox cause form alert on leaving page

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

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)