I've used my USB 3 ASI533MC camera and a USB3 hub without any issues on RPi4. I've connected the USB 2 devices directly to the RPi4, to the ASI camera ports and to the hub. I've disconnected them completely and plugged them back in, never a problem except for the AVX cable connecting to a USB / Serial Prolithic adapter, unplugging it requires a reboot to get it going again.