Obviously I would need more detail to say anything and what size and what not and why it didn't show or anything, just be aware that if you are in there with a hidden order between bid and ask it's completely normal that you aren't getting filled on a bid dump and the lower bid gets the shares, that's not unusual, market makers don't like to fill bids in between, it happens if you are lucky but it often does not. Many years ago that was different, they were almost always filled, right now they hate to fill those unless it's a bigger retail size that gets traded.