Have you resent the config? In CM 521 You set the default for your machine. In my case I have an XXL with HDZ and the Z was set to 90MM and after writing to the forum Will Adams told me to set it to 140/150 for HDZ.
So after setting the default config, and correcting if necessary, you have to send the configuration. So it is a two step process to load your config.
I dont have a laser but some people send a config for use with the laser and maybe that is what has changed your config. Usually when the Z goes the wrong way it is the configuration. Neil has some macros for sending configurations in 3rd party gcode senders for switching between laser and cnc mode. Look up Neil F (cannot recall his last name right now) he is the expert on macros.