RF28R6201SR/AA-51 not making ice

There is not much ice buildup and the Y-clip kit is installed. I used the test button and the harvesting arm moved a little but probably not a complete cycle. When it stopped it did not fill with water, which makes me think 1 of 3 things:

1) the harvester wouldn’t get to the correct position

2) the temp sensor is defective and won’t call for water (it was 3* F so correct temp)

3) inlet valve, but I can’t find a part number

The customer has replaced the filter in the last week and water dispenser works fine. Any additional tests or recommendations how to figure out what part is defective, or the most common problem with this model is appreciated!🙏