I am sure that the explanations provided explain a good percentage of the "missing" listings, and I have followed all these hints to find mine, and even contacted Airbnb "support" - who repeated the above suggestions. But they would never acknowledge that my listing would not show up - at all. They kept repeating it must be my fault, or the browser, etc.
Actually, it would show up if I was logged in. But if I logged out and then did the identical search - no listing! Which explains why my number of enquiries dropped from 10/wk in June to 0 (yes ZERO) in July (you know, high season in the Hamptons).
And although Airbnb would not admit it, it became clear from the hints, that I was being punished for rejecting many potential guests in June. I realized that I would be punished for the rejections by having my listing downgraded, but it is not stated anywhere by Airbnb that your listing will be DELETED for rejecting guests.
And guess what, my "sentance" was commuted in August when I started to get enquiries again.... Full disclosure - I threatened Airbnb with complaints to the FTC and to NYS Division of Consumer Protection.
So, to all you mentors, yes - many newbies post the same question, what do you expect? But , in this case, there is more to the problem than the standard newbie issues.