it appears that you are adding this "guest" as a user in your azure. Correct me if i am wrong. This would make them part of the company, and not by definition, a guest. Also probably a bad idea for many reasons, even though it does solve the problem. (security,
access to corporate resources, having to involve IT department instead of being self serve, administrative burden creating and destroying users for one offs, remembering to kill their account later, etc)
We ended up having to pay for a zoom account to do this now. Zoom just works 100% of the time and in all situations.
So now, whenever we want to have guests join us, we use zoom instead of teams. very sucky but microsoft is not what one would consider nimble in responding to users concerns. I've been working with M$ for over 20 years and they have never cared about the
user. They dont have to, they have our money.