## Context
auth() and currentUser() return null on the server side in the Next.js App Router, even though the user is signed in client-side.

## Verified resolution
Contributor jescalan (after the reporter contacted support): the requests carried an Authorization header that did not contain a Clerk JWT. Clerk treats a present Authorization header as the auth token, so verification fails and auth() returns null. Fix: do not send unrelated Authorization headers to Clerk-protected routes, or ensure the header carries a valid Clerk JWT.