Do you know (from looking in the BIOS) which type of USB controller (1.0, 2.0 etc) is on the motherboard?
There are 3 options you can supply to io-usb. Those are uhci, ohci and ehci for the various types of USB controllers. My guess is the default start under 6.3.0 isn’t supplying the one you need.
Try doing a ‘io-usb -duhci -dohci -dehci &’
Then try the usb -v command again and see if it spots your thumbdrive.
If that doesn’t work, you can try starting io-usb with just 1 of those arguments at a time until you get the right one.