BOM component changing automatically

Hi Members,

I im in strange trouble. For one specific plant BOM component quantity changing automatically. This is happening for few components not for all components. My process is a process industry. We are receiving Planned order from APO, every time when we are checking we found there is quantity deviation wrt equivalent BOM quantity for those specific components. Once we are manually refreshing those planned orders, then rectification is happening. I could not understand the exact issue from where this component quantity is getting changed.

FYI

Base quantity is not changing.

No manual Planned Order change can be done by user

Please help me to resolve this issue as it is urgent.

BR

Siva Sakar