Range Failed Error for Find()

Hello all,

I am getting an error with my code: 1004 Method 'Range' of object '_Worksheet' failed at the lines indicated below. The code still doesn't work when I set j = 11 & k = 40, but the code DOES work if I set the range to A11:A40. Any ideas as how to remedy this? I need to be able to change a lot of variables with the macro, including the range being searched, which is why I have a mess of ranges specified as cells.

Points for helping!

Sub Macro1()
    Application.ScreenUpdating = False
    
    Dim i, j, k, m, n As Integer
    Dim wb1, wb2 As Workbook
    Dim ws1a, ws1b, ws2 As Worksheet
    Dim Txt As String
    Dim s, t As Range
    
    Set wb1 = ThisWorkbook
    Set ws1a = wb1.Sheets("Data Locations")
    Set ws1b = wb1.Sheets(ws1a.Cells(8, 2).Value)
    Set wb2 = Workbooks(ws1a.Cells(3, 2).Value)
    Set ws2 = wb2.Sheets(ws1a.Cells(4, 2).Value)
    j = ws1a.Cells(13, 3).Value
'    j = 11
    k = ws1a.Cells(13, 4).Value
'    k = 40
    m = ws1a.Cells(11, 4).Value
    n = ws1a.Cells(15, 4).Value

    For i = 2 To 100
        Application.Goto ws1b.Cells(i, 1)
        Txt = ActiveCell.Value
'        Set s = ws2.Range("A11:A40").Find(Txt)
        Set s = ws2.Range(Cells(j, 1), Cells(k, 1)).Find(Txt)  <----
            If s Is Nothing Then
            Else
                Application.Goto ws2.Range(Cells(j, 1), Cells(k, 1)) <----
'                Application.Goto ws2.Range("A11:A40")
'                ws2.Range("A11:A40").Find(Txt).Activate
                ws2.Range(Cells(j, 1), Cells(k, 1)).Find(Txt).Activate <----
                Set t = ActiveCell.Offset(0, m - 1)
                Application.Goto ws1b.Cells(i, n)
                ws1b.Cells(i, n).Value = t.Value
            End If
    Next i
    Application.Goto ws1b.Cells(2, n)
    Application.ScreenUpdating = True
End Sub