Have you ever checked the "Hidden Posts" on your business Facebook page?
The Scoop on Facebook's Hidden Posts:
In an attempt to filter out spam, Facebook sometimes catches a legit comment in its snares. If you've ever gotten what seems like a phantom notification and can't find the comment anywhere, chances are it ended up in the hidden posts. Check there regularly to be sure you aren't missing engaging comments! You can "unhide" the post to display it on your wall.