Your USB 3 controller is not compatible. I had the same issue pop up after upgrading my motherboard (I'm assuming you've also upgraded recently since you're on x570). A PCIe USB 3.0 expansion card will fix it, but WindowsMR is notoriously picky when it comes to USB controllers that work without issues.

This one is known to work well: https://www.amazon.com/Inateck-Express-15-Pin-Connector-KT5001/dp/B00FPIMJEW/ref=sr_1_29?dchild=1&keywords=kt5002&qid=1610154288&sr=8-29&th=1

An external hub did not fix this issue for me. My issue was resolved with a card very similar to the one linked above.

Be sure not to install usb drivers from the manufacturer, but rather stick with the automatically installed Microsoft ones.

I'm talking about something like this.

Inateck PCI-E to USB 3.0 (5 Ports) PCI Express Card and 15-Pin Power Connector, Red (KT5001) https://www.amazon.com/dp/B00FPIMJEW/ref=cm_sw_r_cp_apa_i_H9C6CbF4E3KYB

You would need 2, 1 for each guest. You can pass them through to each guest just like your graphics card.

BTW, I'm using the card I linked to above in my build running proxmox as the host and it works beautifully with both Windows and Linux.