Songs are sync but won't play

[AlexisM94]

Some of my songs which are in offline playlists and saved in 'My music' don't play. When I click on the songs, the time bar is running, but there is no music and when I touch the pause button, the time bar goes back to zero. I tried de-sync the songs, erase them from my music many times... The fact that I'm online or offline doesn't change the problem, the songs won't play, even if I start the song from the artist's page. It's very annoying because I just can't listen to these songs except if it exist different version of them on the artist's page (e.g.: if I synced the album version and it doesn't work, I can listen to the single version, but if there is only one version, I just can't listen to the song)
I'd be really happy if someone could help me, cause it's very annoying...

[AlexisM94]

By the way, I'm on iPhone 6 running iOS 8.3 (but I already noticed the problem with iOS 8.0.x , 8.1.x and 8.2) (and the problem wasn't present on my iPhone 4 with iOS 7.x)