That's what my problem is with the current release version (12.0.1)... I have a hub that will only work if it's connected to my USB-C dock (which itself I suppose is a hub). With Big Sur (and the i9 MBP... not sure which of those two is the culprit) I had this hub connected to another hub that was connected to the dock and it worked fine.And another update..the usb problems actually got worse. I can no longer chain hubs.