Music skips songs after exactly 30 seconds on only some mp3s, possible iCloud Music Library fiasco

I’m at my wit’s end. Has this happened to anyone or can anyone help? Closest to this problem I can find is an archived Reddit thread from 2 years ago.

Here’s what happens: New music added to Music–usually an mp3 gotten from Bandcamp or download coupon from an LP–may or may not play all the way through. I’ve checked the files in other players like Quicktime. They work. If I scrub past the 30 second mark, the file plays all the way through. I’ve checked the files on my phone, and they work there too. I’m an Apple Music subscriber. My understanding is it should either go up to iCloud or play natively on the machine if not matched. Either way, I’ve got good files and they should just play.

The latest batch is some stuff unlikely to be matchable in Apple. None have the iCloud icon next to them. Not even the ghost-y dotted one. Some songs play, some skip. I had this problem through 2017, and it seemed to have sorted itself out after several months of back and forth with some super genius who eventually just ghosted me. We thought we had tracked it down to having something to do with whether it was synced to iCloud Music Library. Not all songs synced did this. But the only songs that did do this were synced.

Does anyone have any ideas on this? With the latest iteration of the Music app, I’m not even sure how to force to iCloud Music Library or remove from it.
Here are screenshots of one recently added album that’s afflicted. It plays and looks good on iPhone. Apple Music app? Nope.

Two albums recently added to Music show various states of iCloud icon. Screenshot below. One (Doug Martsch, Radio Boise) is most certainly not available on iTunes or Apple Music. The other (Clarke and the Himselfs) is available on Apple Music, but these files were bought and downloaded from Bandcamp.