Using Sleep function to pause code

[pujo]

Using a simple "Sleep" function to toggle color of text in a cell.
Wanting to achieve 500 millisecond between alternations however, Sleep 500 is not giving me the half second pause and more like a 5 second total time.
I've changed the value from 500 all the way down to 0.5 and minimal change in alternating time. Best I can get is 4 second s to alternate 3 times.

Am I missing something?

Option Explicit

#If VBA7 Then ' Excel 2010 or later
Public Declare PtrSafe Sub Sleep Lib "kernel32" (ByVal Milliseconds As LongPtr)
#Else ' Excel 2007 or earlier
Public Declare Sub Sleep Lib "kernel32" (ByVal Milliseconds As Long)
#End If

Sub BlinkText()
  Application.ScreenUpdating = True
  
  ActiveSheet.Range("InspectionDate").Activate 'Named range X11:AD11
  
  Dim i As Integer
  For i = 0 To 2
      With Selection.Font
          .Color = vbRed
          .Bold = True
      End With
      Sleep 500

      With Selection.Font
          .Color = vbBlack
          .Bold = False
      End With

      Sleep 500
  Next
End Sub

 

[pujo]

After a PC restart, it seems to be working correct.....