Sage 300 2019 - OE Committed Qty allowed even when there is no Qty Available

SUGGESTED

My client is using Sage 300 2019 PU4.

Allow Negative Inventory Level in IC setup is NOT selected.


Some users are able enter the Qty Committed for an item  for example, ‘N0006’ and insert and carry on with the order onto the next order line without any warning or error message.

However, when the user posts the order, at that point he receives an error message, the OE order screen refreshes and he loses the entire order. 

This sometimes happen to an order that has over 100 lines and that is a big issue for my client.
This happens intermittently with 3 users out of 46.

Any ideas why this is happening?

Is there a hotfix for this?

Kind Regards

Caroline