My old phone just died on me yesterday. It used to back up the WhatsApp chat history to my main Google account, which I also used to register the device.
Now I have a new phone, and I registered it to the same Google account. After installing WhatsApp, I tried to restore the Google Drive backup to the new installation. However, when I try to enter my Google account, it tells me "This account already exists on your device"
Somehow after switching apps, WhatsApp assumed I don't want to restore a backup, and now I'm stuck with no history.
Also, when I try to set up the Google Drive backup on my new device, it gives me the same error when I try to enter my Google account; "This account already exists on your device". I can't figure out what I am doing wrong.
Is it just impossible to backup WhatsApp to an account already registered to the same device?