Application setup issues - guardian/manage-frontend GitHub Wiki

OAuth Cookies Not Persisting After Callback

Symptoms:

• After completing the /oauth/callback flow, the expected cookies (GU_ACCESS_TOKEN, GU_ID_TOKEN) are not persisted in the browser.
• The browser receives a 502 Bad Gateway response from Nginx during or after the callback step.
• No visible application error occurs client-side, making the issue hard to trace.

Read here