Hi,
Can you post a sample version ?
Blind shot would be to force the lookup value and array into numbers and use this array formula:
=IFERROR(VLOOKUP(LEFT(C2,20)+0,('Item Cost'!$A$2:$B$9999)+0,2,0),IFERROR(VLOOKUP(LEFT(C2,20)+0,('Cost pull from backend'!$A$2:$E$9999)+0,5,0),"No Cost"))...