DO_CHANGE_SPEED not working?

Hi folks,

This might be the silliest topic so far, but it’s driving me nuts.
My plane refuses to obey any speed commands in auto mode.

It does not change it’s speed on DO_CHANGE_SPEED “waypoints” neither on the actions tab on MP.
It also doesn’t comply with the set velocity for surveys (which I guess is a DO_CHANGE_SPEED command itself).

All tried speeds are bellow my TRIM_ARSP_CM. I use an analog airspeed sensor.

Any ideas on what is going on?