I've got a Sony MRW-G2 CFExpress reader over USB-C. In System Information, it's listed as both a USB 2 and 3 device, which is normal.
What is not normal is that it decodes seemingly randomly what of these speeds it will use. Transferring footage over USB2 speeds (topping at 35 MB/s) is not fun. I do NOT disconnect the reader between these random switches.
Fun

