This is odd, and something similar happened to me... I noticed the keyboard configuration changed during the process, without any intervention from my side. At the TOP right corner of the login showed a Deutsch (German) keyboard layout marked as standard, which was very annoying. I opened the system configuration and reconfigured it back to US International (which is the only one I really need), and everything started to work perfectly again.
So my recommendation would be for you to check the keyboard layout configuration and confirm if the right layout is set to your computer.
Cheers,
Leandro M