A developer recently encountered a frustrating bug after deploying a Next.js SaaS application. On the initial load, the useSession() hook returned an undefined session, but a simple page refresh resolved the issue. This problem was exclusive to the production environment and never surfaced on localhost, creating confusion about the authentication token's integrity.

The root cause lies in the asynchronous nature of useSession(). React renders components immediately, while the hook fetches session data in the background. In production's faster environment, the console log executes before the data arrives, correctly displaying 'loading'. This speed difference explains why the issue remains hidden during local development.

To resolve this, developers must check the session status before rendering protected content. If the status is 'loading', the component should return null to prevent premature rendering. Additionally, any logic depending on the session, such as API calls within a useEffect hook, must be guarded to run only after the session object is confirmed to exist.