I should be extremely specific here, but it is late so forgive me…
I have a FireTV4K running the .26 beta from 2 months ago. I used the Amazon site | Device management pages to Edit the name associated with the device. I called it “Garage”. Plex Server uses "Garage when showing Authorized Devices.
I have a FireTV4K Max running the current .30 beta. I used the Amazon device management pages to assign a name to this device. (“Master Bedroom”) Plex Server does not use my device name when showing Authorized Devices. Rather, it uses “AFTKA”.
I have no idea if it is the difference in Fire sticks. (One is a Max…) Or an issue with the Beta code.
It is useful to rename devices to a logical name. AFTKA is not helpful when I have 4 or 5 FireTVs " deployed.
Cheers