Hi Eric,
I don’t think your locked PO release is being ignored by MRP. I don’t like how this works either, but I think this is the deal: You will not have enough part to satisfy 12/10 job, you cannot move the PO to be received for job because you have it locked, so no expedite suggestions. Therefore system gives you a new PO suggestion because you have a need and you cannot get existing PO there. Since you are using minimum on hand instead of SS on it, I think you are getting the suggestion to come after the Lt of 60 days on the part. I suspect if you had SS of 75, you would get suggestion to have the PO come immediately. You could move your job date to agree with when your PO is coming on 1/4 and then I think you will not get another suggestion.
Nancy