The only way that could be so is if your sheet codename is not Sheet2.

Does this work?

Public Sub Reorganise()
Dim lastrow As Long
Dim nextrow As Long
Dim targetrow As Long
Dim i As Long

    Application.ScreenUpdating = False
    
    With ActiveSheet
    
        .Range("A1:C1").Copy Worksheets("Sheet2").Range("A1")
    
        lastrow = .Cells(.Rows.Count, "A").End(xlUp).Row
        .Range("A1:C1").Resize(lastrow).Sort Key1:=.Range("A1"), Order1:=xlAscending, _
                                             Key2:=.Range("C1"), Order2:=xlAscending, _
                                             Header:=xlYes
        nextrow = 2
        targetrow = 2
        For i = 3 To lastrow + 1
        
            If .Cells(i, "A").Value = .Cells(i - 1, "A").Value Then
            
                If .Cells(i, "C").Value > .Cells(targetrow, "C").Value Then
                
                    targetrow = i
                End If
            Else
            
                .Cells(targetrow, "A").Resize(, 3).Copy Worksheets("Sheet2").Cells(nextrow, "A")
                nextrow = nextrow + 1
                targetrow = i
            End If
        Next i
    End With
    
    Application.ScreenUpdating = True
End Sub