OAuth MCP server works in ChatGPT Developer Mode ("Create App") but fails in App Review form — what does "unsupported OAuth config type" really mean?

I’m having similar issue. The backend log show the error happen after it hit “.well-known/openid-configuration”. Could be some validation errors but the message is not useful at this time. Seems liked this is a new issues. Submitted another app a few days ago with the same oauth config and it was fine.