Good afternoon my name is ***** ***** if the ice maker carries out the operation after the test the only things that are left is either the temperature of the incoming water is higher or the temperature of the freezer is not as cold. Once the water is inside the icemaker tray these are the only two things that have any effect on the ice making speed.
Lets do the answers one side at a time, the ice maker fill is timed and set up in the factory or can be modified by the engineer for low water pressure areas. This is fairly straight forward as in the UK the water companies are required by law to supply water at a pressure between two points. Whilst as you metnion above the water is supplied from the same source once inside the appliance it travels in two directions, the drinking water travels into the fridge area where it is chilled to the set fridge temperature and then dispensed whilst the ice maker water travels up the back and directly into the ice maker.
I hope that clarifies the operation of the two areas same water supply different route into the glass. If so would you now kindly rate the information given by selecting from the star rating system at the top of the page, once done you can ask further questions free of charge, do come back to me if you require further help. In the maintime thank you for using JA and have a great weekend - Ian