I have the Sharkoon purewriter keyboard. I am using Ubuntu 20.04. The keyboard doesn't work after resume. Often it doesn't work in grub, and the last few boots, it didn't even work at login.
I have had it connected to a powered STLab USB 3.0 hub. Now I have plugged it directly into the PC USB slots. It seems to be working, but I didn't try suspend yet. Is there a way to get it working with the USB hub?
I see someone else had this same issue with this keyboard, but there are no answers.
An additional search showed me this problem is common with all mechanical keyboards and ubuntu. But the solution given didn't work for me.
This solution didn't work either. Run sudo gedit /etc/default/grub
the edit the following line
from: GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
to: GRUB_CMDLINE_LINUX_DEFAULT="quiet splash atkbd.reset i8042.nomux"
Help please!