For the past few weeks, I have been running a bot in the Sandbox while testing it to replace another, currently broken, bot that posted new posts and challenge sandbox posts in The Nineteenth Byte. When the bot sees a new answer to the sandbox question or a new post on either CGCC or CGCC.Meta, it sends the link of the question or answer to chat. Normally links to questions and answers in chat will onebox automatically, but a large number of the bot's posts for sandbox answers have not been oneboxing despite being formatted correctly (
Myself and @lyxal did some testing and the issue only seems to occur when GingerBot, specifically, sends a message using my SE Chat API library. Using the same library to send links with a different account and using the web client to send messages using GingerBot's account both worked fine.