Hi @dcooney
There was a bug on version 5.1.5 that was affecting the loading of select2 I believe this is related.
The bug was fixed on the next update 5.1.6.
You can also use the acf/input/admin_enqueue_scripts action to register / deregister / enqueue / dequeue styles
You can check out more info on this action here: http://www.advancedcustomfields.com/resources/acfinputadmin_enqueue_scripts/
