notebooklm-migrated-cookies-rejected-different-http-fingerprint

Valid (non-expired) cookies migrated from the old notebooklm-py storage_state.json are rejected by Google when used via the upstream client. Root cause: the upstream uses different HTTP headers and user-agent fingerprint than notebooklm-py, causing Google to reject the session even though individual cookies pass expiry checks. Fresh cookies must come from the upstream’s own auth flow (nlm login) or directly extracted from a live Chrome browser session via DevTools Network tab.