Hi,
If one you use 501 the stock is sent to Quality inspection, then this could happen because you have checked the Post to Insp. stock indicator in the material master (Purchasinf view).
Post to Inspection Stock
Specifies whether the material is subject to quality inspection (without inspection lot processing) and whether a goods receipt is posted to inspection stock. The indicator is copied to purchase order items and goods receipt items as a default value.
Dependencies
You can select this indicator, if no stock-relevant inspection type has been selected in the inspection setup, and therefore no stock-relevant inspection lots can be created.
If you activate a stock-relevant inspection type, the entry in this field is deselected and can no longer be maintained. In this case, a corresponding indicator in the inspection type controls whether goods are posted to inspection stock.
When you use 501 the stock should be posted as unrestricted stock, then you can move the stock from Unrestrected to Quality Inspection stock using movement type 322 (use t-code MB1B).
With movement type 321 you can move from Quality Inspection stock to Unrestricted.
Kind Regards,
Mariano