The user permissions error is a wpbakery error, you can do a test yourself please:
Download any user role plugin and create a new role, with the necessary permissions to edit posts, pages, etc., except plugins, themes ..

Then try to edit any HTML block previously created by another user, you will see that from the frontend editor you do not have access, instead from the bakend editor yes.

Please, give it a try, you are the only person who can correct this error as I cannot access wpbakery support because it is included with the Woodmart purchase.