I imagine that you’re having a problem deferring ACF scripts because they are localized and the plugin is not handling the localization of scripts properly, but that’s just a guess.
The scripts in ACF also depend on jQuery and several others so you would need to not defer these as well.
If you’re using ACF5 you can look in the plugin file /advanced-custom-fields-pro/acf.php on line 369 and you find a function named register_assets(). This is where all the scripts are registered.
