That is because you are not using the actual Multiple Listing Service. The MLS is the system that houses the real estate listings for sale, but there are "rules" to it's proper use.
You must be a Licensed and "Approved" Realtor - With a Licensed and Approved Broker - and the system you put into place has also to be approved by the powers that be.
You may be familiar with the online systems that say they have the "freshest" real estate listings. Most don't have the permission to publish the listings directly from the Multiple Listing Service.
They use "work arounds" and most of the time are lagging behind the MLS feed, which updates every 7-10 minutes on this page and on our #goSCV website.
In addition, those websites are being used as "lead generators" for real estate agents. They pay the owners of those sites ton's of money to give them your personal and private information. To see what I mean, just give up who you are and wait a few seconds to get called and emailed repeatedly.
I'm Connor with HONOR and have a great system in place to be of assistance when it comes to you searching for real estate and homes for sale in Santa Clarita Valley.