Adobe Connector for Chat GPT can't generate images

The Adobe Firefly connector in Codex is repeatedly failing with:

HTTP 403 Forbidden — “MCP streamable transport probe failed”

Endpoint: https://photoshop-mcp-service.adobe.io/v3-creativity-b8f2a/mcp

The connector worked briefly and successfully generated images, but then began returning this error again. It occurs before Firefly receives the prompt, even when generating one image at a time. Disconnecting, reconnecting and restarting the app have not resolved it. Please investigate the connector’s authentication/transport authorization.