Why GOP suggested date in sales order is incorrect for Make item?

Summary:

GOP is not suggesting right availability date/expected delay for a make item used in Sales order when there is no on hand quantity available. ATP rule was set up with "Supply Chain Availability Search" as shown below. Please advise.

It is not considering lead times defined in ATP rule, it is just considering below item attribute values for a Make item as per Oracle's support person.

Per Oracle support person, GOP uses this calculation —> "For a make flow GOP considers Fixed LT + (Variable LT x Qty) + Post Processing LT"

According to me, it shall consider cumulative manufacturing lead time as mentioned in ATP rule since we need that much time to manufacture and there is no on hand qty avaialble. But GOP suggests much less number of days than anticipated since it considers LT as mentioned above.