Hi @lea, I am using an Android tablet as the viewer device to provide a third screen. The version of the viewer is v0.9.77.
The input seems to be generated by the Spacedesk driver. It is not coming from the hardware keyboard that is attached to my Windows 10 PC. As soon as I stop the Spacedesk driver on the Windows 10 machine the generation of the “\” character ceases immediately and I can happily type on my keyboard as normal. The hardware keyboard is USB wired connection, not a wireless keyboard or software keyboard.