The car is sensing an obstruction or binding of the deploy actuators.
You may want to go under your car and lube the hinge points on your steps .
I find a can of silicone spray does the trick .
don't use grease as it attracts dirt and grime to theses points.
As for switch under the dash this is deploy your side steps and lock them out for maintenance.
There is a sequence to do this .
Engine off, ignition switch on , push and hold lower button, steps will deploy and stay out, turn ignition switch off.
now you can open close the doors and steps will stay out.
Some times the button does not want to play or won't work, I open drivers door then close door wait until step retracts, then turn the ignition on and try button again this seems to work every time.
Note if you start car again and drive off they will retract and work as normal again.
One of the replies said sometimes they do not deploy, this could be if you are off road or driven over a bump , the car thinks you are off road and does not deploy the steps so you don t smack them into a rock or ledge and damage them.
I hope that helps with the gremlins.