I want to provide some assistance. I had trouble getting
virt-manager to redirect USB devices from my Linux Mint Cinnamon
21.1 host to any of my guest virtual machines. I finally
discovered why. The manager assumes that USB devices are USB 2
whereas I was using USB 3 devices. I had to go into each
VM and tell it that the devices were USB 3 type. Then redirect
worked. The virt-manager 4.0.0 needs to be updated to allow any
USB device (including USB 3 and the new USB 4) to be redirected.
Hope this helps for people with the same problem.