I wanted to share a fix in the coding that I found. With regards to the JuiceBox issue, I looked at the plugin and I saw that the viewport declaration was hardcoded in the code. I changed the code and tested Juicebox. It works. Problem fixed (until I upgrade the plugin!). This was related to an issue where the galleries were not displaying properly. It was forcing the site to a certain screen size which on mobile would result in the page rending only the top corner in the viewport and the user wasn't able to scale it either.

With my declaration the entire page is visible on load and it scalable.

I edited the function include_tags() in wp-juicebox.php.

Original:

function include_tags() {
        echo '<meta name="viewport" content="width=device-width, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, user-scalable=0" />';
    }

Update:

function include_tags() {
        echo '<meta name="viewport" content="user-scalable = yes">';
    }