Copy / modify Item coverage via X++

I'm using the ReqItemTable::CopyFromItemId() to copy the Item coverage details from one released item to another. After the code is run I check the ReqItemTable and the record which was copied looks to match. Once I open the ReqItemTable form, I can see the Maximum inventory value looks correct for a split second before it's changed to "0.00". The coverage group also doesn't match what I'm seeing in the ReqItemTable -- meaning the value in the ReqItemTable isn't what is being displayed on the form though the design appears to indicate the ReqGroupId field is used to populate that form control. 

I've not been able to find much on the ReqItemTable out there and i'm hoping someone can offer direction. 

Thank you.