Salvaged Optical Drive doesn't mount

I pulled the optical drive out of my 2011 MacBook Pro, and I’m using an adapter that connects from it to my new 16” MBP. It refuses to mount. System Information shows it is connected, but it doesn’t do anything more. When I insert a CD/DVD, it spins and makes noise for about 30 seconds, then goes quiet. The CD does not show up in Finder.

I have another “universal drive adapter” that uses an external power source. If I manage to get all the cables connected via a Thunderbolt Hub, it works fine. Any ideas why, and how to fix this?