Cookie authentication bug in MEAN app

Current Situation: We have a MEAN app authenticating via SAML. The SAML server is used by another app for authentication as well. When a user logs in via SAML, an auth cookie is created. When the MEAN app is loaded, it checks for the auth cookie, if present, it calls a node backend endpoint. The backend endpoint also checks for another signed cookie. If the signed cookie is not present, it should redirect users to the SAML login page. If the signed cookie is present, it decodes it and uses the resulting value to check for an matching session on the db. If a matching valid session is found, it retrieves and returns the user's details, and extends the session lifetime. If none is found (e.g. if it is expired or something) it returns the appropriate error message. If the response from the backend contains user's data, it is used by the frontend to set the currently logged in user. If it doesn't contain user data, a guest user is set. NOTE: When the backend endpoint is executed directly on the browser, it is able to read the available cookies. Expected Project Deliverable 1) Enable cookies to be detected by the backend when the endpoint is called from the frontend. 2) When the session cookie is missing / expired / invalid, but the auth cookie is present, the app should redirect to the SAML login url.