Is your PO standalone or connected to the work task?

To receive a task-connected PO, the MWO user must have been assigned to the task and the task must have been transferred. This is to make sure that the right technician receives the parts, hence the warehouse/location defined on the PO line details is ignored. The warehouse/ location on the PO line is only considered for standalone POs (i.e., not task-connected).

If your PO is task-connected, what Delivery Method did you select on the Work Task Demand Line?

If your PO is created independently from work tasks, the PO lines need to have Receive Case=Receive to Inventory and the Destination Warehouse ID needs to be set to one of the warehouses that the MWO user is connected to.

My PO is connected to a WT, and the Delivery Method on the PO line is “Normal”

The problem comes from MWO, because when I handle the receipt process on back office, it works, the received part is reserved on the material requisition line and I can issue it :

But when I receive on MWO the receive case in the Receipt is “Receive into arrival”, the part is not in stock or arrivals, and I can’t issue it.

Can you share screenshots of your MWO warehouse?

Here are the screenshots :

Is there a reason why your remote warehouse has an arrival and a picking location? Can you try with picking only? 

When receiving a Inventory Purchase part into inventory, an inventory location must be specified. But you have been able to receive it in MWO without specifying a location which is strange. 

Not sue if it picks a location in the background somehow. So as Alex suggested, please try with having only the picking locations in the warehouse.

Are there any customizations in this area?