Use the sumproduct formula:
PO Formula:
=SUMPRODUCT(('Tracker '!$J$3:$J$38="PO")*(MONTH('Tracker '!$B$3:$B$38)=MONTH(Summary!$A4))*('Tracker '!$D$3:$D$38=B$2)*('Tracker '!$G$3:$G$38))
IR Formula:
=SUMPRODUCT(('Tracker '!$J$3:$J$38="IR")*(MONTH('Tracker '!$B$3:$B$38)=MONTH(Summary!$A22))*('Tracker '!$D$3:$D$38=B$20)*('Tracker '!$G$3:$G$38))