I`ve not bred Cali kings myself but I do know uping the humidity a little may well do the trick.

Give them a wee spray and see if that loosens her up a bit. It may also help to limit the traffic or cover the tanks so the snakes aren`t being bothered at all by passing people or other distractions.... Sorry I can`t be of more help, i`m sure someone else will be able to offer more experienced words of advice