The Gramps hosting of its Discourse forum is on a managed server. It is constantly updated with all of Discourse’s newest abilities.
To quote the catchphrase frequently uttered in the old ‘Monk’ detective TV show: “It’s a gift… and a curse.” Because new behavior pop up unexpectedly.
In this case, Discourse has a rich link preview feature called OneBox that creates a preview. Alarmingly, I think it might be leaning towards ads revenue previews.
But there is a OneBox configuration and troubleshooting thread.