I keep all of my music stored offline on my iPhone 6s (iOS 10.3.3). iCloud is entirely turned off. My iPhone's drive is also nowhere close to being full.
I just recently bought an album, and I'm experiencing this weird issue where the songs in this album keep getting removed and I have to re-download them.
Something that might be noteworthy to mention is that since I bought this album from the U.S. store, the titles were originally in English. I then converted them to their original given names by the Japanese artist (iTunes/Music app has never complained about this in the past).
How do I get the Music app to stop deleting songs from my album?