BADI 'BADI_FDCB_SUBBAS04' is not getting triggered via POST button in simulate window

Hello experts,

                  I have implemented BADI 'BADI_FDCB_SUBBAS04' for MIRO. Its getting triggered and working fine when i post the incoming invoice in MIRO via 'POST' button on the menu. However, if i try to press SIMULATE button and press 'POST' button on the simulate window the BADI is not getting triggered. Please suggest where did i go wrong. Is there any technical limitation of this BADI that it should trigger only via direct post button? Please suggest. 

Thanks in advance,

Shyam.