Please enter the Privacy Protection password to unlock

yesterday i have unlocked my Chuwi Hi9 Air, after the Sim lock Pin i was attempted for the screen lock Pin but i have found the message in object.
of course i have never created this password
surfing with google seems a big problem because many devices are affected by this problem
i have already tried many solution but when i go to reboot the device at the end of boot his display again the message “Please enter the Privacy Protection password to unlock”
the most popular solution is to proceed an HARD RESET of the device of course losing all dat like format for pc
after many and many attempts i have choose the hard reset solution but when i have rebooted the thablet it have showed again the message Pleae insert etc etc
someone can help me to recover my tablet? thnks