Negitive stock

MYOB is allowing negitve stock when invoicing and creating stock issues.

If we have a negitive stock issue on a build item it will not allow us to build as it sends warning message stock value is negitive.

If I do a stock adjustment taking all build items from stock and adding built item same result  we have to add item at zero $ value.

This is a business $ loss.

The usual process won't allow us to invoice into a negitve stock and we need to either receive stock or build the item, we get a warning at invoice stage.

Please advise why this is happening.