Songs from my library not playing without wifi

Hi, all!

Apologies if this question has been asked before, but on my iTunes on my iPhone, about half of my music won't play unless I'm connected to Wifi. As far as I know, I didn't do anything to cause this to happen. The perplexing thing about this is that most of the music is not purchased from iTunes, but has been uploaded from CDs or from MP3s before iTunes existed.

Some side notes- I subscribe to both Apple Music and iTunes Match. I am running on iTunes 12.1.3. As noted earlier, this is something that just happened one day, I didn't change any settings.

Anyone have any idea why this is happening? I like to listen to music in my car, and this is making it very difficult.

Thanks so much in advance!