iOS Music is Suddenly Scratchy Out of the Blue

As the title says… iPhone music is suddenly scratchy and sounds very low quality without explanation. It’s been flawless until now. No recent syncs or anything. Got into the car today and the quality through CarPlay was horrendous. Tried it again with AirPlay (to my Sonos speakers) and it’s equally atrocious. This is my personal library, not streaming music. I do not subscribe to Apple Music or iTunes Match. I do not have anything set to reduce quality when uploading or syncing. I have been managing my music since the very first incarnation of iTunes, through to this messy new Music app, so I am not a newb…. but this has me completely stumped.

Recently purchased music doesn’t seem to be affected. It’s random. When I check the affected albums, there doesn’t seem to be a rhyme or reason for it. One of them has suddenly been labeled as lossless and the bitrate marked as “stream”… quality, but the info is flickering as I hover over it. When I go back later it has suddenly changed to 320 kbps as it should be. Meanwhile, another affected album has always said 320 and never converted to lossless.

When I play from my desktop Music app library to the Sonos speakers… flawless. This is the very file that syncs to my phone—and again, it’s not set to reduce file size. Am I missing something? Everything was fine earlier this week; it’s like a sync happened without my knowledge and changed everything. Restarting doesn’t help.

Incidentally, I keep a second identical copy of all these music files in a Plex library that is steamed from a completely different country. When I use the phone to test out the tracks through PlexAmp to CarPlay and to my Sonos speakers, the music is flawless. This is strictly an iOS Music app problem.

iPhone 15 Pro Max to be specific.