I have a Macbook Pro which I use in combination with a Thunderbolt display.
I also have a standard Apple USB keyboard with numeric keypad which is plugged in one of the USB ports of the Thunderbolt display.
The problem I have is, that the keyboard is often not recognized. Usually when I shut the laptop down and start it again. I usually managed to bring it to work when I unplug the keyboard several times and plug it in again OR I open the settings and wait for some time and do random things.
I don't have any problems when I just put the Mac to sleep. The keyboard will still work when I wake the Macbook up again.
The keyboard works perfectly well when I connect it with the Macbook directly – so it seems not to be an issue with the cable. Other USB devices work in the ports of the display – so this seems not to be the issue as well.
But of course I want it to work with the display so that I don't have to unplug too many things to take my laptop away.
Best Answer
I discovered that when I plug the USB cable of the keyboard into the short USB extender cable (that came with the keyboard) and then plug the extender cable into the Thunderbolt display, it works for me. Maybe it will work for you too.