Some of the sites (like this one) don't have fields for "tenure" (that defines leasehold and fee simple.
I have mentioned this to them several times, but they don't have that field, or it is halfway down the page.
In the MLS, the word "Leasehold" must be on the listing if it applies. The sames goes for advertising, but as i said, the agents can't control what is imported into another system.
Please call if you have any further questions.