Any music randomly removed from iPhone, even if uploaded from a CD. Also, music removed and "Not available in my country or region"?

Music is randomly being removed from my iPhone. Some music I uploaded from CDs I entered in my iTunes library using the laptop iTunes app, some I bought on iTunes Store and downloaded it in my library, all this so I can manage the music I listen to from time to time. Now music is being removed from my device, music I uploaded from CDs I legaly bought, but also music I bought on iTunes, all songs giving the message that this music is "not available in my country or region"? So this means if I re-upload those songs they will be removed again? Based on what rules? I paid to legaly listen to that music and encourage the artists who work their heart and neurons off, and this is what I get? And before you ask, I still have over 60Gb space on my device.