How do I set the default permissions for a group doc?

Hi, the code on https://www.ads-software.com/support/topic/how-do-i-set-the-default-permissions-for-a-doc/ works well.

However, when a new doc is being input initially without a group, then a group is chosen from the dropdown, the access permissions refresh and don’t seem to take any notice of the defaults, not good if I don’t want Anyone to be the default. Is there something I’m missing to make a doc that’s put into a group take notice of the defaults too?