I have to say search function on the HDX is super buggy. On music it doesn't work. I type in a term is says 200 results then immediately goes to no results found!
Let's start with a simple song title: Silver Bells now I have probably 25 different versions on the Cloud and it can't find anything. If I type in the letter A only one Album shows up.
I have over 245 Albums on the Cloud that's 4250 songs and it can't find anything.
I am sending in a bug report.