From what I can see the plugin script is moved to the footer, while the initialization is still in the header. I'm guessing it's either a minify/cache plugin doing that.
I think I have a solution, but a minor change must be made in one of the plugin files. I will write down the steps below, if you can't do it, feel free to add temporary FTP details to your ticket, and I will do it for you:
1. Make sure to have site back-up, just in case anything goes wrong.
2. Open up the wp-content\plugins\related-posts-pro\includes\hooks.php file on your server.
3. Scroll to line 63, which should be this:
add_action('wp_head', 'wpdreams_rpp_hooks', 10, 0);
4. Change that line to:
add_action('wp_footer', 'wpdreams_rpp_hooks', 9999999999999, 0);
5. Save the file, clear your cache site cache.
This will make sure to move the rest of the plugin scripts to the site footer, hopefully solving the issues. Let's hope it helps.Best,
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