Some downloaded songs unable to play when offline

[RoastNose]

So until recently, all my songs had worked fine offline, but a few songs have now become unavailable to play when offline even though they are clearly downloaded on my phone. Storage is no issue, and I when I go onto a single of one of these songs that won't play, it says downloaded next to it and above the single cover. This is only happpening to a few songs out of hundreds, but they are some of my favourite songs. I have tried redownloading the songs a number of times and still nothing plays when I go to play them offline. If anyone has any solutions, please help.

[Opatsut]

Try re-installing the app. Or Factory reset your phone!