Hi, Bart! I just wanted to follow up to let you know that I’ve been exploring this – and it’s really weird.
I think what’s happening is that PublishPress is manipulating the post status value in some way, and *something* that WP to Twitter does is interfering with that. However, I haven’t been able to find what PublishPress might be doing or how those could interact.
The error happens because when PublishPress prints their admin scripts that include the global $post object, the post_status is empty, which causes it to fall back to the default value for PublishPress.
If I dump the global post object from WP to Twitter using the same hooks that PublishPress uses (admin_enqueue_scripts or admin_print_scripts), then I get a different result depending on whether PublishPress is active. With PublishPress, the post_status is blank; without it, it’s fine.
That tells me that WP to Twitter isn’t somehow manipulating the $post object (which I expected, since WP to Twitter *shouldn’t* be doing that).
But since I can’t find where or why PublishPress changes the object, I haven’t made any real progress.