There are at least 2 guys from our local forum who tested this. I have unlocked before using 2 account method (which doesn't work now anymore), so I can't test this anymore. Try with your own risk.
1. Login to i.mi.com with the same account with the device.
2. There will a popup banner to upgrade and sign-in, click it
3. Login again
4. Go to Find My device and make sure the device can be found
5. Open Mi Unlock 2.3.803.10 (i don't know which one, try to find it), login, put the device into fastboot, and try to unlock without binding the account. Don't close the mi unlock.
6. unlock failed, restart phone and bind the account at the phone.
7. reboot to fastboot again after binding and try to unlock again
8. It will stuck at 99%, loading without any error message. Somehow the user close the mi unlock after 5 minutes
9. Open the mi unlock again, login and try to unlock and suddenly it success. Phone restart, data wiped and unlocked already.
I don't test this, so if there is something doesn't work, please try to adapt, improvise and overcome it. Make report if it works for you and which step that you follow (or improvise), so other can benefit from it.