USB Serial Problem Windows

Hi,

I want to use virtualhere on Windows 10 to passthrough a denkovi USB Relay Board to a hyper-V guest.
The denkovi boards are based on a FT245R USB FIFO https://www.ftdichip.com/Products/ICs/FT245R.htm

Using it on the host everything works, when I try to use the program from the Guest the driver complains about an invalid handle.
This is the library I'm using: https://github.com/petersbingham/dae-py-relay-controller/tree/master/

Any ideas?

Thanks,
Kanon