MACRO Filtering Table with Msgbox

[Rayreloj10]

I got my macro working in filtering my table upon clicking vbYes in my Msgbox. However, I'm confused bcoz sometimes it filter the other column and obviously I get incorrect filter. Count the column manully correct the code and its worked again and when you tried again will filter another column again.

by the way, im working with multiple excel files here and the code is pretty much the same. I really appriciate someone who can give me explanation here what's happening? is this because of the same coding? I got this vba code below, so as you can see the field is =16 but sometimes it filter =15, this happened after I code the other file. although the field is different, still the filtering is changing.

If NotificationMsg <> "" Then
        If MsgBox("REMINDER:" & " (" & Range("V1") & ")" & " " & " INCOMING PENDING LETTERS." & vbCrLf & vbCrLf & "Would you like to view pending letter(s)?" & vbCrLf & vbCrLf, vbExclamation + vbYesNo, "Pending Letter Reminder") = vbYes Then
        Worksheets("Register").Range("A4").AutoFilter Field:=16, Criteria1:="OPEN"
          bWarning = True
          
          Else: Worksheets("Register").AutoFilterMode = False
             ActiveSheet.Range("$B$4:$T$3000").AutoFilter Field:=16
             Range("B5").End(xlDown).Select
             lngLastRow = ActiveCell.Row
             Rows(lngLastRow).Select
             Cells(lngLastRow, "B").Select

 

[DanteAmor]

The column number to filter starts from the first column of the range to filter.
In one filter you have A4 and in the other you have B4.
They should both start in columna A:

If NotificationMsg <> "" Then
        If MsgBox("REMINDER:" & " (" & Range("V1") & ")" & " " & " INCOMING PENDING LETTERS." & vbCrLf & vbCrLf & "Would you like to view pending letter(s)?" & vbCrLf & vbCrLf, vbExclamation + vbYesNo, "Pending Letter Reminder") = vbYes Then
        Worksheets("Register").Range("A4").AutoFilter Field:=16, Criteria1:="OPEN"
          bWarning = True
         
          Else: Worksheets("Register").AutoFilterMode = False
             ActiveSheet.Range("$A$4:$T$3000").AutoFilter Field:=16
             Range("B5").End(xlDown).Select
             lngLastRow = ActiveCell.Row
             Rows(lngLastRow).Select
             Cells(lngLastRow, "B").Select