Some New Do Not Appear
Listed in Website Problems & Help.
Reply by RobSTAFF 
What is your Favorite TV Series?
This is normal behavior. The newest song additions can take a little while to show in search results. They will be added to the search results though. Normally it takes about a week for the new additions to show in searches.
Post by soundchrisGOLD
Some new songs do not appear when you type the name with all small letters in search. The new Neil Sedaka song is one of them.