Ansible 2.4 not loading group_vars?

I recently updated to Ansible 2.4 from 2.3, and my group_vars no longer seem to be loading automatically. Spent a couple hours looking into it, but since it’s “magic”, I’m not really sure what’s going on.

My solution for the moment is to load them manually:

- name: load vars
  hosts: all
    - name: load vars
      include_vars: group_vars/all.yml

Not sure if this will cause problems if they suddenly start working again. I’ve been considering moving those vars to a better location for reuse anyway, and this will make that easier.