pump under laundry tub works intermittently

[Norma4]

I have a Shellback pump under my laundry tub in my high wall construction home. My washer empties into the laundry tub, however, the pump does not always come on to pump out the water. I have had a number of instances of the laundry tub overflowing and flooding my laundry room. Other than sitting with the washer to make sure the pump works, are there any suggestions as to what I can do to adjust the pump or to make sure that it works every time?