XPS 13 9360 Bit locker problem: can't enter letters from keyboard

I cannot enter the recovery key on the bitlocker recovery screen because I can enter numbers only but no letters from my keyboard. This is very strange as I was able to enter the full key (letters and numerals) earlier today.

This all started with the "Alert: TP unit cannot be found." issue, a major pain itself! However I did find my recovery key on my Microsoft account and successfully opened the laptop. But not now since letters cannot be entered now.