The SE Chat Bot seems to be unwell. This includes Sandbox Feeds and Meta Feeds.
Neither of these posts were deleted at the time of posting. Does anyone know what's causing this behaviour?
I would hazard a guess that it is related to the recent name change of the meta domain (from
codegolf.meta.stackexchange.com, done as part of the project to make Stack Exchange HTTPS-only. Note that links to the old domain still work via redirects, but perhaps this confuses the feed-bots somehow.
After @MartinEnder changed the URLs, the oneboxing seems to be working again as observed on TNB. Thanks!