I´m not a SPIKE expert, but I encountered this kind of behavior on several solid state pinball machines.
Normally the coil winding for flipper hold is not working correctly in these cases. Kiss Pro seems to have a dual wound coil (Power/Hold with three wires) for the flippers. The power coil winding fires the flipper up then the EOS-switch turns power transistor off. Since hold coil winding is not working the flipper won´t stay up and EOS will trigger power winding again. After some attempts the CPU ends this machine gun cycle to prevent damage. Maybe you should check with a multimeter if hold winding is powered correctly. If you´re lucky is only a bad solder connection on a coil lug.