Oneboxes not created for on our site, work elsewhere

Hello, I am trying to create link previews for this site on our Discourse instance:

As you can (hopefully) see, the onebox works here, but on our instance it does not:

Oneboxes for other sites work fine. What could be the problem, apart from the target website blocking us for some reason? How can I troubleshoot the problem?

maybe have a look at your forum’s various onebox settings go to admin-settings and type “onebox” in the settings filter box at the top. Have a look at this topic:


That’s my guess. If you have lots of links to them you could be rate limited. If they look right in preview but not when the post is rendered, this is the issue.


I’ve asked them about it and they are not blocking us. The link is not oneboxed in preview nor when the post is published. Is there somewhere I can peek at to see the particular error?