I had the same issue on the shake down trip, and remembered on the PDI, the guy showed me the location of the water valve and how it operated. It is located behind the panel under the fridge. I told him to leave the water on, and he left it closed. It is a round push/pull knob on the water line. If you look close, on the end of the knob it says "pull to open". (It is a little stiff to operate). After opening it I turned the ice maker on and off a few times and it started working after a bit. Hope your issue is as simple as that!
2015 Forester 3051SF