Even though this post is pretty old: Did you find a solution for this?

I took everyone's input and found the explicit workflow which I list below.

1. Make sure your Routes are set up properly (Inventory module > Configuration > Routes

    1a. Select Manufacturing

    1b. One this window my "Source Location" was blank hence the POs created instead of on hand inventory being allocated

2. If you have open MOs, cancel and recreate. Upon recreating your "Check Availability" button should reserve the on hand product. If and only if you are out of stock will a PO be created.

problem can be only in several things: some location is different(for mo or maybe you deliver in 2 steps and products are still in 'input' location). or you have all things by MTO and that triggers another po and etc.

create new product and try. o make detail description, what product configuration, what work flow qty and what result you get.

Same problem for me. Stock has been plenish by a purchase, goods is in stock, but when I would like to transfer that goods to another company, it's marked as unavailable and cannot be reserved.

Thanks for any answer. Paolo