Password issues with RoundCube

Just installed Nethserver and added Roundcube. There’s something odd about passwords and keyboard layouts.
I’m using a UK keyboard, and installed NethServer with the UK keyboard layout.
On UK keyboards shift+3 gives you the UK currency symbol £.
On US keyboards shift+3 produces #.
I added a user and set a password that included the £ symbol, then discovered I could not login to Roundcube mail.
Other complex passwords are fine, so long as I only use key combinations that are the same on US and UK keyboards.
Any ideas?

Reset the password in the user list of the UI of nethserver