Working with Exchange Web Services and trying to create a meeting on my calendar. I can get it to work when I just pass the AccessToken with the call to create the meeting. However, when I pass the AccessToken and the RefreshToken with the exact same call, I'm getting an 401 - Unauthorized exception. I suspect I have something configured incorrectly with the portal.azure.com. Any ideas?
However, when I pass the AccessToken and the RefreshToken with the exact same call
You shouldn't be passing the Refresh Token during authentication this is not the way bearer authentication works. The RefreshToken's purpose is for you to be able to get a new AccessToken when the one you have expires (eg every 60 minutes). You need to do your Token management outside of anything you doing in EWS eg before any call to EWS you should check to see if the token has expired and if it has you then use the Refresh Token to acquire a new access token. If you using an Auth library like ADAL or MSAL they will handle this for you.