Trying to understand a permissions constraint for duplicate Stock User

We are trying to create a custom user with permissions similar to the “Stock User” in ERPNext. However, we are finding differences with the permissions on the Items in Stock Entry and Delivery Notes when you go back to edit Draft records.

Can anyone help me understand what might be going wrong?

In the top entry in the image below, If we assign the “Stock User” role to our user, then things work as anticipated. We can open a draft record, edit Item Code, Quantity, etc. in the items table and if we open the details on the item, the fields are editable.

In the lower part of the image, if we create a “Stock User Copy” (same permissions as Stock User) and assign that role instead of “Stock User” then most fields become read-only when we go to edit the draft record. It seems like maybe we do not have permissions to edit existing Stock Entry Items (same thing happens with Delivery Note Items). With this user role, we can no longer edit quantity or item code, and if we open the item, all fields are read-only.

Is there a permission or something we are missing?