Is this your release version?
This is from my System Info:
Rhino 8 SR0 2023-3-14 (Rhino WIP, 8.0.23073.13185, Git hash:master @ 87334dd0c40798c15720a4b20d27d7b220881e46)
License type: Kommerziell, build 2023-03-14
License details: Cloud Zoo
Expires on: 2023-04-28
Anyway, I also see that when an all caps layer name is moved up one parent, the layer name changes back to first letter capital and the rest lower case.