Editors can’t add forms

I’ve added the following code to functions.php to let editors add and edit forms and entries:

/**
** Allow users with the editor role to use the Caldera Forms admin screen
*/
add_filter( 'caldera_forms_manage_cap', function() {
	return 'delete_posts';
}, 51 );

But it doesn’t work. The “Add form” button appears, but after entering a name and clicking the button to save the form it just reloads the Caldera forms admin screen without any form being added. If I log in as admin there is no problem adding a form.

It seem to be the same issue as here: https://wordpress.org/support/topic/give-authors-write-to-use-caldera-forms/