Excel VBA dual Worksheet_change events not working - excel

Question

Having trouble executing both Worksheet_Change events correctly. Image below show my results, when modifying column B, column M does nothing. When modifying column L, column N updates as expected but only on row 2. Every other subsequent change to B or M results in N:2 updating to the current time again.
My desired outcome is that when Col B is updated I record a time stamp in Col M and the same when Col L updates that I get a time stamp in Col N.
Example of Excel Error
My current code is here:
Option Explicit
Private Sub Worksheet_Change(ByVal Target As Range)
Application.EnableEvents = False
Dim rng As Range
Dim rng2 As Range
If Not Intersect(Target, Columns("B"), Target.Parent.UsedRange) Is Nothing Then
On Error GoTo Safe_Exit
For Each rng In Intersect(Target, Columns("B"), Target.Parent.UsedRange)
If CBool(Len(rng.Value2)) And Not CBool(Len(rng.Offset(0, 11).Value2)) Then
rng.Offset(0, 11) = Now
ElseIf Not CBool(Len(rng.Value2)) And CBool(Len(rng.Offset(0, 11).Value2)) Then
rng.Offset(0, 11) = vbNullString
End If
Next rng
Application.EnableEvents = True
End If
ElseIf Not Intersect(Target, Columns("L"), Target.Parent.UsedRange) Is Nothing Then
On Error GoTo Safe_Exit
For Each rng2 In Intersect(Target, Columns("L"), Target.Parent.UsedRange)
If CBool(Len(rng2.Value2)) And Not CBool(Len(rng2.Offset(0, 2).Value2)) Then
rng2.Offset(0, 2) = Now
ElseIf Not CBool(Len(rng2.Value2)) And CBool(Len(rng2.Offset(0, 2).Value2)) Then
rng2.Offset(0, 2) = vbNullString
End If
Next rng2
Application.EnableEvents = True
End If
Safe_Exit:
End Sub

Answer 1

Mock-up, untested, change of code to simplify as you're doing the same actions in two spots:
Option Explicit
Private Sub Worksheet_Change(ByVal Target As Range)
Application.EnableEvents = False
Dim columnLetter as String
Select Case Target.Column
Case 2 'B
columnLetter = "M"
Case 12 'L
columnLetter = "N"
Case Else
Goto Safe_Exit
End Select
Dim loopRng as Range
For Each loopRng In Range(Cells(Target.Row, Target.Column),Cells(Target.End(xlDown).Row,Target.Column)
If IsEmpty(loopRng) = True And IsEmpty(Cells(loopRng.Row,columnLetter)) = False Then
Cells(loopRng.Row,columnLetter) = Now
ElseIf IsEmpty(loopRng) = False And IsEmpty(Cells(loopRng.Row,columnLetter)) = True Then
Cells(loopRng.Row,columnLetter) = vbNullString
End If
Next loopRng
'Columns(columnLetter).NumberFormat = "yyyy/mm/dd"
Application.EnableEvents = True
Safe_Exit:
Application.EnableEvents = True
End Sub
Note that the IsEmpty() = True is important... when using an If case, you need to specify for each condition, otherwise the implicit detection will fail.
Edit1: Removed Intersect from loop, whereas the range i've listed will need corrected... it at least references a specific range, now.
Edit2: Removing .Offset and working with specific column references in cells().

Answer 2

I tried this version of my original code and it started to work for some reason.
Option Explicit
Private Sub Worksheet_Change(ByVal Target As Range)
If Not Intersect(Target, Columns("B"), Target.Parent.UsedRange) Is Nothing Then
On Error GoTo Safe_Exit
Application.EnableEvents = False
Dim rng As Range
For Each rng In Intersect(Target, Columns("B"), Target.Parent.UsedRange)
If CBool(Len(rng.Value2)) And Not CBool(Len(rng.Offset(0, 11).Value2)) Then
rng.Offset(0, 11) = Now
ElseIf Not CBool(Len(rng.Value2)) And CBool(Len(rng.Offset(0, 11).Value2)) Then
rng.Offset(0, 11) = vbNullString
End If
Next rng
End If
If Not Intersect(Target, Columns("L"), Target.Parent.UsedRange) Is Nothing Then
On Error GoTo Safe_Exit
Application.EnableEvents = False
For Each rng In Intersect(Target, Columns("L"), Target.Parent.UsedRange)
If CBool(Len(rng.Value2)) And Not CBool(Len(rng.Offset(0, 2).Value2)) Then
rng.Offset(0, 2) = Now
ElseIf Not CBool(Len(rng.Value2)) And CBool(Len(rng.Offset(0, 2).Value2)) Then
rng.Offset(0, 2) = vbNullString
End If
Next rng
End If
Safe_Exit:
Application.EnableEvents = True
End Sub