Could you please provide details but what you mean by "any device that is connected to the backup poe switch does not show up."
I am going to answer you questions inside your post.
Does not get POE power?
The devices do get power, but that is it. Once connected they are not able to route anywhere nor does their MAC address so up in the table.
Get power but the MAC is never seen in the ethernet-switching table (which can only be shown via the Master RE)?
The ethernet-switching table will show which port that MAC address is connected to and no port from the POE switch shows up
Can we assume the VC is actually up and running properly?
Yes, all the ports show up correctly.
I even took the troubleshooting one step further and I switched the switches membership priority. So now the POE switch is the primary and the non-poe switch is backup and I am still having the same issue with the POE switch.