Problem with playing imported songs when using mobile data

[S1lvaa]

Hello community, I have a weird problem with my spotify android app. I have some songs in playlist that are imported. I got them synced to my HTC One M8. But there is a problem. When I start listening without connection to the internet everything is ok until I turn on my mobile data. Since then when I chose to play one of those imported songs, it plays around 1 second of it and then the next song starts to play. I still didn't find anyone with same kind of problem, so that's why I am asking here. Thank you for the answers