New songs stuck in "Waiting" in Mac OS Music app

I've added songs over the past several months to Music app on Mac OS but they remain firmly ensconced in "Waiting" status and will not go past that.

Note: I've already consulted Apple tech support. That was a waste of time. The person I dealt with had difficulty understanding what I was telling them, but once they did understand, nothing they suggested made the slightest difference. Not my usual experience with them.

Based on what that person told me, Apple clearly doesn't consider this a problem that even needs to be fixed. Which I disagree with, but hey, I'm just a computer owner, right? What the heck do I know, right? I'm just an idiot who threw thousands of dollars at Apple over the years, right?

Now then ... I've tried de-authorizing Music on my Mac then re-authorizing it. I've restarted the app literally thousands of times. I've restarted the Mac literally hundreds of times. I've reset PRAM, SMC, whatever.

I've also tried disabling library sync in Music preferences, which leads to some interesting results:

• Simply disabling library sync causes Music to crash; at restart, it shows library is still syncing, despite my having disabled it, which caused the app to crash in the first place
• I've opened Music in safe mode then disabled library syncing; in that case the app doesn't crash, but if I check Music preferences again, I see syncing is still enabled

So, Music literally refuses to permit library sync to be disabled. Is there some way to disable library syncing then re-enabling it, which the Music app will honor (because at the moment it doesn't care what boxes I check or uncheck, assuming it even stays running)?