Not sure what you mean with USB A, but both flash stick and WD My Passport work fine when plugged to my Mac Pro, but nothing when plugged to mixer. I only can plug those to USB A port on mixer (has QU-drive label). The USB B port I use to connect to Mac, but that doesn’t work either.
I tried reset via shutting down mixer, than pressing Reset and Setup buttons when powering up. All faders went down so I believe it did the reset, although there was nothing written on display saying the reset was done. I also tried to reset my mac. Still looks like usb connectivity is broken.