No longer able to forward emails from exchange online

I have a couple of developers helping me out with a project so I've given them access to my teams so we can collaborate. I am in Office 365 and exchange online.

Last summer I set up forwarding on their accounts so I could send meeting invites from within Teams and it was working great. I don't remember exactly how I had it set up... But I know I didn't have any licensing applied to their accounts. I did create an account for them in my Azure AD and set up an external alias on their account. But I don't remember if that was what made it work to start out or not. Regardless, it's not working now.

At some point last winter, it stopped working. I didn't have time to deal with it so I just forwarded the meeting invites to them from my outlook.

I did some looking out there and found a recent (Feb 23, 2023) article from MS stating that a user must have a valid / licensed account for forwarding to work. But I know this was working prior...

I now have time again and since these people aren't employees, I don't want to provide them with a mailbox. But I do want to be able to forward meeting invites from Teams to their outside email addresses.

Any ideas on how I can get this to work? My requirements are being able to send MS Teams meeting invites to an external user to my system.

Are they currently guest users in your tenant?

To me if there is no special need, you do not need to setup forwarding to send meeting invitation email to them.

You can directly add them as attendees by using their email addresses when you create the meeting in Teams or in Outlook, they would receive the invitation email in their external mailbox.