RCS Thrusters Behaving Strangely

I am making a satellite probe that maneuvers using an ion thruster. To rotate it uses rcs thrusters. These thrusters work perfectly fine until the stage before the ion thruster is jettisoned. They then cease working at all. The probe itself has monopropellent, solar panels, battery, and xenon. The last working stage only has an rp 1 tank and a mage engine. The rcs thrusters are active and there is still monoprop left in the tank.