Formatting Multiple Series in a Chart

I had the same experience on the first time through but when I changed the line back and ran the macro again, it changed both. It also changed both when I stepped through the function. I'm not sure what is going on.

This change works for me,

Sub x()
    Dim objSeries As Series
    
    With ActiveChart
        For Each objSeries In .SeriesCollection
            With objSeries.Format.Line
                .Style = msoLineSingle
                .Transparency = 0
                .ForeColor.RGB = RGB(40, 56, 24)
                .Weight = 0.75
            End With
        Next
    End With
End Sub