Hey @david-blox,
Thank you for reading our tutorial.
Unfortunately, I’m not able to reproduce the error you reported.
I assume you cleared the local authentication data after logging out (see the logout() function in auth-service.js).
Do you get any log entry in your Auth0 dashboard related to the authorization code exchange?
Also, a track of the HTTP messages exchanged between the app and the Auth0 server could help to understand what is happening.
It would be great if you can provide this further information.