Anthropic's Vercel MCP connector has been failing to connect since Aug 13, 2026. Error shown:

Your account was authorized, but Vercel returned an error when connecting.

This has occurred consistently across three separate attempts, including after clearing cache on both the Anthropic and Vercel sides and retrying — which rules out a local caching issue on my end.

Anthropic's own support team checked their status page and confirmed no matching incident on their side. Their read on the pattern ("authorized, but error when connecting") is that it typically traces back to the provider's own MCP server — possibly a firewall/WAF blocking Anthropic's outbound requests, an issuer/audience mismatch in OAuth configuration, or a token endpoint timeout.

Reference IDs from the three failed attempts, for matching against server-side OAuth logs at these timestamps:

• ofid_eed6a84b42586c52
• ofid_a30d7a1f0e5ae00c
• ofid_ebc2564ced07efb3

Team affected: brandbeatglobal-codes-projects

Has anyone else seen this, or does anyone from Vercel have visibility into what these correspond to on the MCP server side?