Accounts Payables discount not posting a Journal

I have a client who's vendor is giving out some accessories with a 100% discount in a certain month. On Purchase order, the client is capturing  this accessories with the previous cost but discounting it at 100%.

The challenge is and I stand corrected, we expected Journal to DR Inventory and CR  Discount Received but apparently no Journal is sent to the GL but in the inventory Movement report, we can see this accessories increasing. Is there a solution or better way of doing this? Please assist.