For a week I’ve had Cloudflare Access working fine with a generic OIDC provider configured to Auth0. However today Cloudflare Access commences the authentication flow by redirecting to Auth0, but following successful authentication the redirect causes Cloudflare to render a page:
Failed to fetch user/group information from the identity provider
Apologies, Please contact your Access administrator
Despite this the Auth0 admin UI logs report “Success Exchange” and “Success Login” events.
I have tried the obvious things (using a different browser, clearing all history and cookies, rotating the OAuth Client Secret, creating a new application in Auth0 then a new OIDC provider in Cloudflare) but none of them worked. A review of https://cloudflarestatus.com shows no outages, although something similar happened on 16 October.
Any suggestions what to try or how to troubleshoot this?