How to get backdated posts to cross-post?

I’ve recently created some posts that I backdated one or two days, and just today noticed that they didn’t cross-post when published. I’m guessing this is correct behavior for cross-posting, but how do I get them to cross-post after the fact?

There is no manual crosspost as far as I know.

And you’re correct, this is expected behavior in current implementation (back dated posts don’t cross post)