As it appeared, the on-screen keyboard for entering the unlock password is missing English layout, although it for sure was present when the password has been created. Now the situation appears really bad:
- the phone (TP-LINK Neffos C9A, Android 8.1 NFUI 8.0) is locked,
- the password is not possible to enter because of missing keyboard layout,
- option for adding keyboard languages is not available,
- there is no option "Forgotten password" and
- Android Device Manager responds "Can't reach device" with either WiFi or 3G connection.
How to unlock the phone in such situation?