What is exactly the problem? Does nothing happen? But it is charging correctly?
Did you try for testing, force file transfer as standard usb configuration under developer options?
If not and dev options are not unlocked: Settings > About tablet > click serveral times on “build number” > back to settings > system > developer options > default usb configuration> file transfer.
If it is not helping.. mhm you still have warranty? Send it back or try installing a custom rom or less extreme try an app like localsend until alldocube hopefully fix the problem if it is software side.
