WP Speed changes during automatic missions

Hello Community, I experienced a little strangeness on my hexacopter with firmware version 4.5.1 and the Cube Orange+ flight controller, when carrying out a mission the drone speed exceeded the speed limit that I had set.

I set the WPNAV_SPEED speed to 2m/s, but when the drone is carrying out a mission it can exceed 2m/s or can be 2.5m/s several times

Are there other parameters that I need to set besides WPNAV_SPEED?

Thank you