I have a custom plugin that creates an 'advanced' (I've tried 'normal' too) context meta box. When I call the 'save_post' action, the $_POST array does not contain any of the form data stored in the meta box.
If I modify the context of the meta box to 'side', the $_POST array has the form data stored in the meta box.
I can't find any mention of this in the documentation. I'd like to keep the 'advanced' or 'normal' context as the form inputs are quite wide. Any idea why this may be happening?
Thanks in advance.