I tried to setup WhatsApp for my friend’s phone number and restore “msgstore.db.crypt12” from phone’s internal storage and it worked. But the same step isn’t working for my phone number. In my phone number’s case, WhatsApp always looks for a backup in Google Drive to restore from, even if I’ve deleted the google account in the phone and the internet connection is switched off.
WhatsApp will first search for your logged in account and look for any WhatsApp backup files in your Google Drive with the same phone number. If you’d like to prevent WhatsApp from backing up using your Google account, simply delete the WhatsApp backup folder (instead of logging out your Google account from your device).
If your local “msgstore.db.crypt12” are using the same phone number on your new WhatsApp, the setup will then use your local file to continue restoration.
Hope this helps.