luiginumberone

To anyone following this thread, the issue was resolved by creating a new VM config and pointing it to the original vdisk img file. Booting the VM using the new config correctly shows the GPU and USB controller in the client as you would expect. Booting with the old config does not - this is repeatable.
 
I checked the new XML against the original and there were no significant differences so I'm not really sure what caused the new config to fix the issue. I've uploaded the two files if anyone cares to inspect.
Things that changed:
Name UUID NVRAM fd path Target port and slot for PCI index 4, 5, 6 I wouldn't expect the first 3 items in this list to be of any significance.
I manually changed the original config to use the new Target port and slot for PCI index 4, 5, 6 and it did not resolve the issue, so this seems not to be the cause either. I'm stumped, but at least things are working now on the new config.
 
I'm still left with an issue where my Windows 11 VM hangs at the shutdown screen when the USB controller is passed through, but that seems like a separate issue and I'll deal with it in a new thread if required.
Windows 11 Fix.xml Windows 11.xml