British Airways says my randomly-generated password is invalid

I attempted to create an account on today, but repeatedly failed, receiving the message “Error: The password you have supplied is invalid. Passwords need to be at least 6 characters in length and use a mix of letters (English A-Z) and numbers.” I tried the following randomly generated passwords: awseecfejunknyZVWCNQPAVZUTE57264 nxmsgnkgqSYHXDPRJRRGGKKTHCE52872 edmzuszfecUVWSFHVCBHVBAV84822792 vdntgfssatdHMRPZNMWVPTVCBZA32444 […]