Hoping this will help those who are also struggling with the problem.
It took me a while and a lot of frustration to realise that my USB cable of NanoKVM-PCIe doesn't fit. It was slightly blocked by the PCI bracket of the case, this was really not obvious (=~ 0.2mm) but enough to prevent it from working time to time. I had to physically cut it to be able to fully insert the cable connector in the socket. And now the keyboard works perfectly!
Hoping this will help those who are also struggling with the problem.
It took me a while and a lot of frustration to realise that my USB cable of NanoKVM-PCIe doesn't fit. It was slightly blocked by the PCI bracket of the case, this was really not obvious (=~ 0.2mm) but enough to prevent it from working time to time. I had to physically cut it to be able to fully insert the cable connector in the socket. And now the keyboard works perfectly!