Perhaps you could try it without using filter:
Private Sub Worksheet_Change(ByVal Target As Range)
Dim wb As Workbook
Dim YEE As Workbook
Dim ws As Worksheet
Dim uCols As Integer
Dim sMnth As Date
Dim dRng As Range
For Each wb In Workbooks
If wb.Name Like "YEE*call placement*" Then
Set YEE = wb
Exit For
End If
Next wb
If Target.Address = "$B$1" Then
For Each ws In YEE.Worksheets
If ws.Name Like "YEE*DEPT*" Then
uCols = ws.UsedRange.Columns.Count
sMnth = ws.Range("B1").Value
Set dRng = ws.Range("A:A").Find(Target.Value, , , xlWhole)
Range("B4:Y4").ClearContents
dRng.Offset(, 1).Resize(, uCols - 2).Copy
Rows(3).Find(sMnth, , , xlWhole).Offset(1).PasteSpecial xlValues
Application.CutCopyMode = False
End If
Next ws
End If
End Sub