Analytics - JWT token is incorrectly formatted, and cannot be decoded

[adamm54417042]

We're using the new JWT functionality for Analytics API v2.0, following https://www.adobe.io/authentication/auth-methods.html#!AdobeDocs/adobeio-auth/master/JWT/JWT.md

We're using the jwt.net libraries and eventually seem to have everything hooked up, but we're still getting this back in Postman when we try to exchange the JWT token for an access token:

{

    "error_description": "JWT token is incorrectly formatted, and can not be decoded.",

    "error": "invalid_token"

}.

Comparing our token to the one generated in the adobe.io console, jwt.io is showing that they're both decoding fine, the only difference is that our token has an extra Typ header:

So I have two questions:

1. Why would adding an extra Typ:JWT header cause an error?

2. Does anyone have any ideas how to remove that header?