For what purpose Lot Cost Process create data in GMF_LOT_COST_DETAILS with negative header_id and ha

We are using Lot Cost Type for Fiscal Policy since 2009 with R12.1.2.

Lot Cost Process running by schedule almost every day.

Now if we run this script:

select count(*) from apps.gmf_lot_cost_details lcd

WHERE NOT EXISTS ( SELECT 1 FROM gmf_lot_costs lc WHERE lc.header_id = lcd.header_id) 

the result = 115071808

and 90% with negative header_id

And it will increase from day to day.

The question is Lot Cost Process create data in GMF_LOT_COST_DETAILS with negative header_id and have no link to GMF_LOT_COTS ?

Is it normal or just garbage that need data fixed to cleared that record.