Water can spill if the pressure is too high,the fill tube leaks or is not positioned properly in the fill cup. Ideal water pressure for this is 30-35 psi. If the pressure is higher it could be causing it to splash. If the fill tube has a crack it will splash or leak during fill. Sometimes moving or readjusting the fill tube slightly will prevent splashing as it enters the fill cup. A couple of other possibilities would be if the fill cup or fill tube is frozen. This will cause the water to either splash as it hits the fill cup or cause the water to back up and leak out at the tube joint. You can check how the water fills by jumping the ice maker. There are some test points on the module. With a well insulated jumper place it between terminals L-V and water should flow so you can see what is taking place. I'm sending a picture of the test points. Before inserting the jumper unplug the refrigerator from the wall outlet and after the jumper is inserted reconnect the plug. If you perfer leaving it plugged in while checking be very careful as this will be a hot test. If you need more assistance you can resubmit your question with more details.