@petemandeDid you have any luck with this? I'm having the same issue. The invites look fine as long as the recipient is NOT using outlook on the desktop. A bit surprising as I would have expected things to work better with outlook.
@Glenn Chubak well yes, but purely by chance and not by any intervention on my part. As I got no replies here I used another tool for online meetings. Last week I tried again to send invitation from Teams and lo and behold, everything now works as expected. Sorry, but I can't help you as I don't know the reason why this is working now.