Hello, as I've had this same problem and I've been able to fix it thanks to this thread, I would like to add my grain of salt with what I've done.
Initially my Onyx boox Max would show up as a "lemobile" device, as mentioned by another user.
1) First thing I did was to uninstall the driver from the device management window and reboot. Once rebooted I reconnected and chose to add the driver manually in the dialog given. I've installed the Google driver provided in one of the previous posts, and it shows up as "Android ADB Composite interface" (I've attached a screenshot of the details)
2) Once the driver was installed as shown in the photo, I again clicked on "update driver", "choose manually from a list" (the latter is the option located below "let windows update the driver automatically"), but THIS TIME I CHOOSE "USB composite device". I'm a complete ignorant on drivers, but I understand the Onyx boox Max needs 2 drivers, one to communicate through the USB interface itself, and one to be able to engage using the ADB protocol. After I added the USB composite device driver, the Onyx book Max started showing in explorer as a storage device as it should (it shows up with two different letters, one for the internal Boox's memory and one for the SD card)
Hope this helps someone
