I’m trying to add Pipedream’s hosted MCP server (https://mcp.pipedream.net/v2) to Open WebUI using the built-in OAuth 2.1 flow.
When I click Authorize on the Pipedream consent page, it redirects back to my Open WebUI instance, but Open WebUI immediately shows this error in the URL: OAuth callback failed: missing_claim: Missing 'nonce' claim.
Authorization should succeed and Open WebUI should be able to store the token and connect to the MCP server.