I have checked with MIDI-OX and my PC is receiving input from my keyboard. When I add a midi-track, the name of my keyboard is listed in the Inspector, but Cubase doesn’t react at all to keyboard input.
When you say Cubase doesn’t react do you mean no input showing on the MIDI input meters as well as no sound?
Thx for the reaction Problem was solved by changing USB port.
Though it might not have been the cause of the problem you might want to check that your USB ports aren’t going into hibernation to save power.