CUNY Academic Commons

We're tryign to get some students onboarded for a project but don't have CUNY email addresses for all of them. I told our project team that they could invite non-CUNY email addresses, and that people would have to sign up for a CAC account with a CUNY email address if they didn't have one, but apparently the system isn't allowing invites to go to non-CUNY users. (please see screenshot)

This is not how I thought the system was supposed to work or how it worked in the past. Can you please remind me whether we changed the way it is supposed to work? thank you!