Restrict level filter for Frontier Restrict Backend not working.

Hi,
I have installed Frontier Post, Frontier Restrict Backend, Frontier Restrict Media, and Frontier Set Featured.

I added the following code to my child theme functions.php file:
// ****- Set restrict to allow Author and above -****
function my_restrict_backend_level($min_allow_capability)
{
return “publish_posts”;
}
add_filter(‘restrict_backend_min_cap’, “my_restrict_backend_level”,10,1);

I created a local WP user with the WP Author role.

When I create a new post, I’m able to access the image library, upload images and insert into the post with no problem. But when I click on the Select featured image link it takes me to the default home page instead of the image library.

What am I missing?

On the Frontier Restrict Backend plugin description, I do get a Warning: This plugin has not been tested with your current version of WordPress. Could the one point version change with WP 4.9.0 to 4.9.1 be causing this issue?

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