The following ticket has been risen :

https://fix.lcs.dynamics.com/Issue/Details/1619062?kb=4583258&bugId=506965&dbType=3&qc=8ee06646493f93667e4a4bf105a7d3c8a6cc88a06252706e217a6b11695203f6

506965

Unable to post packing slip for Project purchase order return when negative physical stock is not allowed

Currently, it is not possible to post a packing slip on a project purchase order return, if the negative physical stock is not allowed.

Even if the operation is "neutral" (-1+1) due to the project sales order (item requirement).

The issue is supposed to be settled, but we can see it is not working. (MS bug risen : TrackingID#2410071420002627)