I have a column with values "OB" followed by several values "IB" and I wat to
see if there is a value different from these and return its row.

that's my array function "={MIN(IF(AND(C3:C500<"OB",
C3:C500<"IB"),ROW(C3:C500),12345678)}" but it's not working correctly

However, when I want to find the first value different from "OB"(in my case
thats the row of the first "IB" value) I use the function:

"{=MIN(IF(C3:C500<"OB",ROW(C3:C500), 12345678)}" and it's working correctly.

Can anybody tell me what's wrong with the first formula and what do I have
to change in it?