planned order generation restriction

my scenario is MTO with an FG that has an SFG in its BOM. The FG's requirements influence the SFG's planned orders. however, the SFG has a standard lot size of 12,000. i am using lot size EX, and have set min & maximum lot size of 12,000. in OMI4, i also have set option 1 : Lot for Lot rounding.

there is a 1 pc is to 1 pc relationship between FG & SFG. expect in MRP run, system will not generate an extra planned order if FG requirements exceed lot size of SFG. Example, FG order is 12,0001.

SFG planned order should not be 2, only one with qty of 12,000.

However, system generates 2 planned orders, both 12,000. system is creating an extra planned order, to meet the extra 1 pc requirement. can i restrict this?