I am not sure I will solve your problem, but maybe give some
input. I had a similar problem (That the ‘<‘ key to the right of
the left shift key on ISO-style keyboards didn’t work) on a Bell
Labs Plan 9 on my Raspberry PI (though it might nowadays, it is
an old installation on that sdcard). It does however work on 9front
on my Pi. If I remember correctly, I had the key working on a PC
running Bell Labs Plan 9 if I connected the keyboard to PS/2, but
not when connected to USB using a converter. But again, on 9front
it works both on PS/2 and USB on that PC for me.

Jonas


<-----Ursprungligt Meddelande----->
  From: Jens K. Loewe [jens.k.loewe@gmail.com]
Sent: 24/7/2019 9:57:27 PM
To: 9fans@9fans.net
Subject: [9fans] Trying to make 9front work on QWERTZ 

Ahoy,

I've been trying to give 9front a test ride for a while now, and I'm
stuck with one specific problem.

So I have a German keyboard layout where <, > and | are on the same
key. However, while I have no problems with these keys, in 9front the
key seems to be dead on all of my keyboards. I tried quite a lot of
them, both inside QEMU on two different computers and on a dedicated
ThinkPad. Also, using the de layout does not fix that.

Is that a known problem or a configuration error?

.