When I search for a location, why do some of my Favorites not appear in the search results?

I have been working on my iPhone 6 (with iOS 8.4) to add some map favorites in Apple Maps for a road trip I am taking. However, when I test out the favorites, by using the Apple Maps search feature, some of them appear and others do not. What is the trick to getting a favorite to actually show up in the search.

Also, if anyone from apple is reading this, I would like to see an improvement to maps searching abilities. I can access my Favorites from the Search field, but when I use the Start and End field areas, I cannot. This is easily scene by following this use case:

1) Open Apple Maps and search for a favorites location

2) When the pin shows on the map, select the ">" icon

3) Then select the "Directions From Here" link

4) The directions pane appears with the pin information loaded in the Start field

5) Notice that there is no "Favorites" option to use. When I type a favorite location I know, then I have a hit or miss chance of it actually appearing in the search results (my original problem).

Thanks for any help or suggestions that can be provided.