On one of my machines, I notice that it doesn't respond to the USB keyboard when I am in the bootloader. I haven't tested the other machine yet.
Normally I control these workstations through SSH to the BMC and it is a long time since I tried using a directly connected keyboard so I don't even remember if this worked before
I tried two different keyboards. Both keyboards work fine with other workstations.
When Linux and GNOME boots on the Talos II, the keyboard begins working
In the bootloader config, I found an option to choose between hvc0 and tty1 consoles. I don't know if that should make any difference but I tried both settings and it didn't help.