It looks like the token shared is from a different authorized app - The sub claim should be the client_id of your brokerx-secure application. Basically, it looks like you just need to use the brokerx-secure credentials to get an access token as opposed to the application with a client_id beginning in WidyZzQpW....
It might be worth checking out the “test” tab of the Management API in your Auth0 dashboard - You should just be able to grab an example access token from there. If that is working then it is most likely a configuration issue with your CURL or however else you may be obtaining tokens.