Fill/Copy Down Blank Cells Issue

I'm trying to fill down various columns based on the cell value above it, and have found various examples in how do so including the below macro.

But what I'm finding is that this does not always work. I have found that for cells that are formatted as Text, the macro returns the =R[-1]C instead the correct cell value.

Sub XFillInBlanks()
    Dim Rng1 As Range, Rng2 As Range
    Set Rng1 = Selection
    On Error Resume Next
    Set Rng2 = Rng1.SpecialCells(xlCellTypeBlanks)
    On Error GoTo 0
    If Not Rng2 Is Nothing Then
        Rng2.FormulaR1C1 = "=R[-1]C"
        With Rng1
            .Value = .Value
        End With
    End If
End Sub

Is there a way to fill blank cells without having to first change the formatting back to General?