VBA Code for altering a series of data

I have a workbook with a column of 1's and -1's. I want to go through with a loop and alter that data in two instances. If the column produces (1,-1,1) or (-1,1,-1) I then want it to change that third value to be equal to the second value and move on down the column. I have some VBA to accomplish this but it does nothing when I run it. It might be something simple or I might be way off base, either way any suggestions would be appreciated. Here is what I have.( Two options)

Sub Alter_data()
    
    Dim cell As Range
    Dim Rng As Range
    Dim x As Integer
    
    Do While (x - 1) <> (x - 2) And (x - 2) = x
    x = x + 1

        If (x - 1) <> (x - 2) And (x - 2) = x Then
        x = (x - 1)
        End If
    Loop
    
End Sub

OR

Sub Alter()

    Dim i As Integer
    Dim r As Range, cell As Range
    
    Set r = Range("B2:B4248")
    
    For Each cell In r

        If (i - 1) <> (i - 2) And (i - 2) = i Then
        i = (i - 1)
        Else: i = i
        
        End If
    Next

End Sub

Presuming that your data is in column A

Sub alterdata()

Dim i As Long
Dim lr As Long

lr = Cells(Rows.Count, 1).End(xlUp).Row
For i = 3 To lr
    If Range("A" & i) <> Range("A" & i - 1) And Range("A" & i) = Range("A" & i - 2) Then
        Range("A" & i) = Range("A" & i - 1)
    End If
Next
End Sub