Application.Intersect Not Working

I'm using the following code to check the value of a cell:

Private Sub Worksheet_Change(ByVal Target As Range)
    Dim KeyCells1 As Range
    Dim KeyCells2 As Range
    Dim KeyCells3 As Range
   
    ' The variable KeyCells contains the cells that will cause an alert when they are changed.
    Set KeyCells1 = Range("J5:J100")
    Set KeyCells1 = Range("L5:L100")
    Set KeyCells1 = Range("N5:N100")
       
    If Not Application.Intersect(KeyCells1, Range(Target.Address)) Is Nothing Then
       
        If IsTime(Target) = False Then
            MsgBox "Cell " & Target.Address & " is not a valid time."
        End If
       
        ' Display a message when one of the designated cells has been changed.
        ' Place your code here.
        MsgBox "Cell " & Target.Address & " has changed."
       
    End If
End Sub

For some reason the "If Application.Intersect" line returns "Nothing" when I click cell J5 even though the value of Target.Address is "$J$5".

Any ideas why that's happening?