Ready to posI’m troubleshooting an Auth0 Native application using Authorization Code Flow with PKCE.
The application exists in my Auth0 dashboard, but authentication consistently fails with:
invalid_request: Unknown client
I’ve verified that the Client ID and tenant hostname in the failed Auth0 logs match the registered application exactly.
The failure reproduces in Chrome and Edge. The authorization request includes the expected callback URL, audience, and PKCE S256 parameters.
Can someone explain what could cause Auth0’s authorization endpoint to reject a Client ID that exists in the same tenant?
Is there a way to verify application registration consistency or determine whether this requires escalation to Auth0 Support?t? 
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