Confirmation Control Key changed automatically in Stock Transfer Purchase Order

Hello Everyone,

We have a scenario where we create a Custom Stock Transfer from Manufacturing Plant to Finished Goods Plant.

The Process is Users would scan from MII for a 131 and system would post a 351 Mvt with respect to a Custom Purchase Order [Doc Type ZUB,similar to UB] , moving the stock to IN Transit . Thereby Finished Goods Plant would receive the stock using MB01.

They would use the same Purchase Order every time.

Now we observed some how the Confirmation Control is changed to 0004 and after the stock is moved to In transit,we are not able to receive the stock using MIGO.

What are the Option to change the Confirmation Control key back to Blank ?

Let me know if you need any more information.

Thanks,

Sai Arala.