It's not only fakes - there is always a very large gap between what is available and what is listed online in honest buildings. Humans not marking move-outs or lease signings in realtime always creates a gap as do move-in dates. Buildings tend to only list what's available until the end of the month not 60 or 90 days out when you may actually want to move.

The best solution is to contact the building but this is time intensive and you get a lot of spammy followup which is why we created https://fless.io to automate this process and help you find what is actually available and not just what zillow or the management company's website lists. It's still the best way to know what is truly available.