Sorry but creating a meeting in teams is almost completely disjointed from the equivalent process on Outlook. Half of the features are missing on the Teams side. I can't even see other people's calendar or add people from my contact list outside of the org. It's terribly integrated.
I think that's your organizations settings. I have virtually the same process to make a meeting in Teams as I do in Outlook. Both are easy. I can definitely add anyone from my contact list, including those outside of my org.
