Getting 403 with Amplify's API even though I'm signed in

Considering that I have included all the required portions to set a project up until running Amplify.configure(....) portion

When I run Auth.signIn('', 'password'). It is succeeding. When I take the retrieved access token and test it in the Cognito authorizer tester, it is succeeding. When I run API.get('apiname', '/api/path/requiring/authentication') It is failing. Sometimes with 403 and others with 401 codes. Am I missing something? Do I need to explicitly provide auth headers?

If I remove the auth requirement in API gateway on the same paths, API.get… is working

Have you tested your APIs using the CLI in this chapter?