To everyone who is having trouble with this rescanning issue: Here is something to try.
I spent the morning experimenting with different kernels in Audiolinux. I first did a complete system update and then updated the Audiolinux menu to current (217). Following that, I updated the kernel. When doing this, one is given three choices 1. Audiolinux RT, 2. Audiolinux RT BFQ, 3. Audiolinux RT BFQ 4.19.x.
I had been using option 3 as a stable option for quite a while, but it lost stability with Roon build 536 (and 537). Likewise option 2 is completely unstable. However option 1, Audiolinux RT, is stable. I have rescanned several times, and my number of albums has remained constant (and correct).
My recommendation to anyone having Audiolinux rescanning problems is to try the non-BFQ kernel. I will repost in case instability arises again.