Having trouble playing my "Local Files" on my iphone 6

[ItsManky]

title says it all. i cannot play a large amount of my local files. here are some characteristics of my problem which may help you with a solution

1.  all my files are in mp3 format
2. all sources are highlighted in my preferences and the file destination has not changed
3. the files are all playable on my desktop
4. the songs are un highlighted on my phone client
5. tried resyncing and unsyncing my device
6. all versions of the client are up to date
7. premium subscriber