Bug
The og:image and twitter:image meta tags on https://umami.is point to http://localhost:3000 instead of https://umami.is, breaking social media previews.
Evidence
Inspecting the source of https://umami.is:
og:image → http://localhost:3000/opengraph-image-j8qpfc.png?opengraph-image.98b200b6.png
twitter:image → http://localhost:3000/twitter-image-j8qpfc.png?twitter-image.4736fd2a.png
Root cause
Missing metadataBase in the Next.js root layout metadata export.