Correct unlock procedure.

1. Remove microsd card from phone.
2. Check battery level (it's important, without battery phone can't connect to pc)
3, Remove battery from phone fo 5 sec, then replace it back in phone.
4. Connect Phone to usb and put phone in FAST BOOT MODE (make sure it is in real fast boot mode and other mode will kill signal on phone) then let it install drivers, if drivers conflict will not work ok).
Fast Boot Notice (if keep pressed for 5sec and it s stuck on clepsidre or logo but not recognized correctly, you need to keep it pressed for 5 more sec).
5. Press unlock.(if you press check phone before you press Unlock then YOU MUST repeat same from steps from number 2).

PS. For how to enter correct fast boot mode it is explain in help button in Huawei TAB
PS2> Phone will hang on white screen with little circle in the middle or on logo = That is fastboot. Pc will recognise as Android Sooner Single ADB interface