I have a network of 23 tablets Chuwi Vi7 in kiosk mode. Irregularly disconnected from Wi-Fi networks (period of 2-5 days) and never fail their reconnection. It is necessary to reboot. It's not dependent on the type of Access Point and security. I use WPA2-AES, but it manifests itself in the same way as with any other type of WPA.
Sometimes after a reboot Wi-Fi remains off and shows "Turning Wi-Fi on...." It required repeated restart.