A first-party POST/PUT/PATCH/DELETE returned a 2xx with no Authorization or session cookie present, suggesting the endpoint may not enforce authentication (a broken-access-control smell worth an authorized active test).
A first-party state-changing request (POST/PUT/PATCH/DELETE) returned success with no Authorization header or session cookie present. If the endpoint does not enforce authentication, anyone can invoke it directly; this is a strong lead for a broken-access-control test.
Unauthenticated data modification or deletion, and often broken object-level authorization (IDOR) on the same endpoints.