Music app says my own mp3 files are unavailable in my region?

So I have an old CD-collection that I converted into mp3 files years ago. Just got my new macbook so I imported all the files into the Music app on the laptop and then I synced the entire collection to my iPhone. (I transferred the files by connecting a cable to my iphone and then I choose the option to sync my entire music library to the iphone.)

I don't have a "music" subscription so I'm only expecting to play my own mp3 music on my iPhone for now.

However now I have realized that some music is being prevented for playback. Like this old Lenny Kravitz album "Mama Said" there's track that are grayed out and I get the "This song is not currently available in your country or region".

I mean, that would make sense if I was using the music streaming service from Apple, but I just hours ago copied all the MP3-files for this album to my iPhone. (Or at least that what I thought I was doing.)

What am I missing here?

Sorry for the bad english, I'm a Swede.