Hi folks - I have had several issues with QHY cameras and connections recently and after a lot of installing/uninstalling drivers/registry cleans, I got the 32-bit SGP to connect over USB3.
I could not get SGP64 to, however. I then guessed (correctly) that the all-in-on QHY driver installer does not know SGP64 and does not put the necessary SDK files into the SGP program folder.
You need to manually navigate to the QHY SDK folder and add the contents of the x64 folder to the SGP64 program folder.
It now works. I have requested QHY to add SGP64 to its installer pack, so you there should be no need to do this in the future.