TYPO3 13 enforces a Content Security Policy in the backend whose img-src only allows the backend's own host, data: URIs and the YouTube/Vimeo CDNs. The frontend references its favicons on the CDN, so yoast's snippet preview showed a broken favicon (CSP report: img-src blocked https://cdn.ep-reisen.de/fileadmin/user_upload/favicon/ep/favicon.ico). Co-Authored-By: Claude Opus 5.5 <[email protected]>