Workbook automatically saving in different places problem

Hi,

Since a few days my excel workbook is behaving kinda strange...
It's supposed to auto save when closed. Lately, it doesn't only save in the original location on the server, but also in other places, even local.
Whenever a user opened a folder in explorer and then afterwords opens and closes the workbook I'm talking about, a copy is saved to the folder that was opened earlier and is still active.
What makes it even more strange is that this doesn't always happen, and that the changes made to the workbook are only changed in the Original workbook and not in the copy...

The code I use to auto save is this one:

Private Sub Workbook_BeforeClose(Cancel As Boolean)
    Application.DisplayAlerts = False
    
With Worksheets("Algemeen")
 
  If .FilterMode Then
    Application.ScreenUpdating = False
    .ShowAllData
    .EnableAutoFilter = True
    Application.ScreenUpdating = True
  
  End If
  
End With
    
    ThisWorkbook.Save
    Application.DisplayAlerts = True


End Sub

Anyone an idea what might be causing this?

Thanks in advance!

Tommy