Posting a message "https://chat.stackoverflow.com" in chat shows a picture for Stack Overflow that links to the stackoverflow.com homepage

Question

Look here:

I posted this message in Chat:

https://chat.stackoverflow.com/

It oneboxed like if I had posted

https://stackoverflow.com/

This doesn't happen with a link to https://ja.stackoverflow.com:

so this can have exceptions. Testing in the sandbox, https://aaaa.stackoverflow.com does not onebox as anything.

Testing with https://chat.scifi.stackexchange.com/, chat.{valid site.stackexchange/stackoverflow}.com oneboxes as that site's homepage, making posting a plain link to Meta's Chat, main Chat, or Stack Overflow's Chat impossible in Chat.

Can this be fixed, please?