Michael, while as usual Emily is correct, you should also contact your listing agent to see how she set up Internet posting in NTREIS. In the Office Information section of the listing are several fields that control how and if the listed is transported to other sites or not.
IDX sites of Members
are all independent selections, plus there is a gating field to Display on Internet Y/N and whether the address can be displayed.
Your Realtor may not realize that one of these is set wrong or it may have slipped through the cracks. Most IDX fed sites will have the listing within 24 hours. A few save bandwidth by not pulling the listings so often from NTREIS or even by taking only the main picture and leaving other media untouched.