Worksheet_Change Event won't run more than once

Hi,

I'm trying to set up some code to run whenever a cell is changed. When I open the workbook and change the cell, the code works, but if I change the cell again, the code doesn't run. If I close the workbook and reopen it, the code again runs perfectly once and then doesn't run if the cell is changed a second time. There are no errors, it seems that the event simply doesn't initiate.

Here is my code for reference:

Private Sub Worksheet_Change(ByVal Target As Range)
    If Target.Address = "$D$17" Then
        Dim Loc As String
        Loc = Target.Text
        Dim Count As Integer
        Count = 101
        Do
            If ThisWorkbook.Sheets("IO").Cells(Count, 1) <> "" Then
                Application.ScreenUpdating = False
                Application.DisplayAlerts = False
                Application.EnableEvents = False
                Dim wbOpen As Workbook, File_Name As Variant, strWbk As String
                strWbk = ThisWorkbook.Worksheets("IO").Cells(Count, 10).Value
                Set wbOpen = Workbooks.Open(strWbk)
                Dim Eligible As Boolean: Eligible = False
                For Each cl In wbOpen.Sheets("Tariff").Range("Location")
                    If cl.Value = Loc Then
                        Eligible = True
                    Exit For
                End If
                Next cl
                wbOpen.Close
                ThisWorkbook.Worksheets("IO").Cells(Count, 20) = Eligible
                Count = Count + 1
            Else
            End If
        Loop Until ThisWorkbook.Sheets("IO").Cells(Count, 1) = ""
        
            'Sort the Fields by Eligibility
            Range("A101:AI2000").Select
            ActiveWorkbook.Worksheets("IO").Sort.SortFields.Clear
        ActiveWorkbook.Worksheets("IO").Sort.SortFields.Add Key:=Range("T101:T2000") _
                , SortOn:=xlSortOnValues, Order:=xlDescending, DataOption:=xlSortNormal
            With ActiveWorkbook.Worksheets("IO").Sort
                .SetRange Range("A101:AI2000")
                .Header = xlGuess
                .MatchCase = False
                .Orientation = xlTopToBottom
                .SortMethod = xlPinYin
                .Apply
            End With
            Range("D17:E17").Select
    
    Else
        Exit Sub
    End If
End Sub

You disable events and never reenable them.