Issues With Motor Testing

In testing my motors for my Hexacopter, I see that a signal is getting to the motors as they vibrate, yet they will not spin no matter how why I spin the throttle. I am running the copter on a Pixhawk 4 and do not know what issues I should look at outside of my connections which are all done properly. The safety button is also at a solid red. I greatly appreciate your help in his matter.