I' m trying to implement a stock configuration for my company. So first I created the following stock locations:

• Storage (view)
• • Input (view)
  • Main stock (view)
    
  • • Shelf 1 (internal)
    • Shelf 2 (internal) 
    • ...

Note that input and main stock are virtual stocks, no stock movements must be applied. Only shelfes are allowed to receive goods, if there are incoming goods, they are controlled by putaway rules to get to the right places.

Then I configured a single Stock Type for now

• Incoming goods (Type Incoming, default target: Input, show detailled operations, show reserved)
  

Next I created a simple route:

Default route:

• Action: Buy, Type: Incoming goods, Target: Main stock (so if goods needed in stock, an automatic purchase order is created)
• Action: Move To, Type: Incoming goods, Source: Input, Target: Main stock (so if goods are coming from Input, push them to main stock where putaway rules are getting applied)

OK, now everything is working fine for the following cases:

• When I create a purchase order, the correct stock picking is created. The default route sends the goods to Main Stock
• When using the "restock" function, everything is working fine, a purchase order is created, next the sock picking and everything is sent to Main stock nicely

BUT: when I create a *customer order* and the product is not in stock, an automatic purchase order is placed correctly. Then when applying it, the stock picking sends the goods to "Input" and then it gets stucked --> the route is not applied, even the automatic purchase order looks exactly the same as the manual created one.

Why does the default stock route not get applied to an automatic purchase order (even if I have to confirm it manually exactly as a manual created one)? I cannot find a reason for this. This is our very basic use case, there are even more to implement later, but I'm getting already stucked here.

Where is my mistake? Thanks in advance