local ALAC files suddenly missing from library

TL;DR:

Songs missing from Music.app library. All local alac files in dir solely managed by Music.app. Songs still in dir but don't show up in Music.app as they used to. Files all intact, playable, work fine if manually re-imported.

Contacted support, no help. Only solution found is Doug's Apple scripts.

How do I prevent this issue from reoccurring?

Questioning if choosing Music.app for managing my losless music was the right choice.

--- the long way ---

In the Music app on mac it shows a total of 8.053 songs in my library.

However /user/Music holds 8.225 music files.

The dir is solely managed and added to by the Music app.

The files in that dir were downloaded either directly as alac.m4a or as .flac and and transcoded to alac using xld. The files are all placed into the dir on import by the Music app.

I recently noticed songs missing from my library in the Music app.

Going into /user/Music reveals the files of the missing songs are still there and play fine using QuickLook for example.

After manually importing the file again in the Music app it shows up and plays just as before.

The songs missing don't follow any pattern. Singles / single tracks from albums. Some added more recently some older.

I don't have an Apple Music subscription, nor do I use Sync.

The device is not logged into any apple id / icloud anywhere.

The Music app is for locally stored alac.m4a files only.

There is Doug's Apple Script Media Folder Files Not Added that can find the missing files so I don't have to manually sort trough 8000+ files to find whats magically vanished from the Music app.

But having to pay money for Apples failure to keep a simple database intact is not going to happen.

My Question:

Does anyone know why this happens?

The issue seems to be ubiquitous enough to warrant someone making and updating (ver2.5 as of writing) a tool for this precise issue.

I have just been in contact with apple support, not to say that I've wasted 1.5 hours of my life.

I got bounced from one chat support agent to the next and had to re-explain the issue over and over again.

I got escalated to 'specialist support' via phone who understood the issue even less, despite them having the whole chat log of their previous colleagues redundant questions on hand.

Their solution? Sort through the 8000+ files manually to find whats missing.

How can such a basic issue that should be known to Apple since at least macOS 12 still be around?

If I already have to transcode everything I add to their proprietary format I at least expect things to work but I feel like I put my money on the wrong horse using the Music app if not even the basic task of keeping track of locally stored music files is stable enough to not break in under one year of usage.