vba code stops after 3600 rows

I have code to place items from one apreadsheet to another. It has worked for a couple of years. Now it doesn't pick up any rows beyon 3689. I have a table with 4000 rows and 21 columns. the code moves only 3 of the columns from "MASTER" to "COMPLIANCE" by row based on a date and an if then .

Is there an error in the Code? and why would it stop at that row?

Here is the code.

Sub MoveItCOMPLIANCE()
  
    Application.ScreenUpdating = False
    Sheets("COMPLIANCE").Select
    Range("B3:L7000").Select
    Selection.ClearContents
    Range("B3").Select
    Sheets("Master").Select
    Dim Lastrow As Long, r As Integer, c As Integer
    Lastrow = Sheets("Master").Range("A65536").End(xlUp).Row
    
    For r = 1 To Lastrow
       'FIRST IF ID THE DATE
       'SECOND IF IS THE BLANK APPT CELL
       
       If Sheets("Master").Cells(r, 5) = Range("A1") Then
       If Sheets("Master").Cells(r, 8) = Sheets("Master").Cells(r, 10) Then
            Sheets("COMPLIANCE").Cells(r, 3) = Sheets("Master").Cells(r, 7).Value
            Sheets("COMPLIANCE").Cells(r, 4) = Sheets("Master").Cells(r, 3).Value
            Sheets("COMPLIANCE").Cells(r, 2) = Sheets("Master").Cells(r, 2).Value
            
   
    End If
         End If
    
    Next r
    
    Sheets("COMPLIANCE").Select
    Range("B3:L20000").Select
    ActiveWindow.ScrollRow = 1
    Selection.Sort Key1:=Range("B3"), Order1:=xlAscending, Key2:=Range("D3"), Order1:=xlAscending, Header:=xlGuess, _
        OrderCustom:=1, MatchCase:=False, Orientation:=xlTopToBottom
   
    
    Range("C2").Select
    
    
    
 
End Sub