Inserting formula using vba is adding unwanted brackets

I am adding in a formula using the following code:

With Sheets("Static - Returns")
        On Error Resume Next
        lLR = .Range("l" & .Rows.Count).End(xlUp).Row
        With .Range("m9:m" & lLR).SpecialCells(xlCellTypeBlanks)
        .FormulaR1C1 = _
       "=IFERROR(INDEX('Static - Order Data'!G:G,MATCH(RC[-9],'Static - Order Data'!D:D,0)),"""")"
       End With

When it enters the formula, though, it is adding an unnecessary brackets so that the formula does not work (highlighted in bold).

Formula:

=IFERROR(INDEX('Static - Order Data'!G:(G),MATCH(D9,'Static - Order Data'!D:(D),0)),"")

Any ideas why it is doing this and what I can do to stop it?

Thanks