Something to be aware of the Lightroom catalog itself (which is unrelated to the OP's problem) is that it's an SQLite database. (Or it was when I ran into my problem about a decade ago bit I believe it still is.)
I had hardware-related flakiness with a Windows system at the time. I swapped it out for an iMac but sometime later I discovered that there was some residual corruption of my Lightroom catalog even though I had restored a backup that seemed to be OK. Fortunately I was able to use some SQLite tools to largely fix the catalog.
I had hardware-related flakiness with a Windows system at the time. I swapped it out for an iMac but sometime later I discovered that there was some residual corruption of my Lightroom catalog even though I had restored a backup that seemed to be OK. Fortunately I was able to use some SQLite tools to largely fix the catalog.
https://bitmason.blogspot.com/2013/01/recovering-corrupt-lig...