Device update triggers factory reset and completly locks user out My father made a installed as system update on his huawei gx 10.

After the reboot a message stated that the device was factory reseted and that it was necessary to log in with a google account that synced from this device.

First of all, not factory reset was made. At last not by a local user interaction. I hope all the data is still there and the message is incorrect. Of course my father made no backup. At last not willingly. Maybe some app-data was backuped to his google account, I'm not sure how to check what exactly is there.

I changed the Google accounts password because I assumed somebody remote-wiped it. But now this looks unlikely. It was probably a faulty update.

Second, the authentication does not work. This device only ever used one google account. When attempting to log in there is a message that this account wasn't previously used on this phone. This is false. When logging in to the account from a computer I can see the history of devices that where associated with it. This phone was associated with this account. However the phone lists two devices: "Huawei GX 10" (last activity 22h ago) and "Huawei GX 10 (new)" (last activity 10 min ago). Nobody in my family or my father ever owned a GX 10 besides this one. Maybe this is due to the fact the OS was updated? I don't know what version was running on it previously and don't think i can find out the current version right now. The whole problem would probably a way less serve if google recognized that these two phones are the same.

In summary, I have physical access to the phone and access to the google account, but can't get past android device protection.

Did this happened before? Is there any hope that does not involve desoldering the flash chips?
Called both android and huawei support. Neither of them was helpful. Both insisted that this shouldn't happen, althou the google support said he once had a similar case from a huawei consumer. Both suggested to delete the phone from list of devices in the google account. That didn't work and neither could tell why it didn't and how it could have helped.

Huawei accepted it as a repair case. The phone is still in the warranty period, so i hope for a replacment phone.