Recognizing New Sheet as Last - excel

Question

I have multiple workbooks running the same code, but behaving differently.
I think a user manually moved worksheets; changing the order.
The code uses
tempWs.Copy after:=ActiveWorkbook.Sheets(Worksheets.Count)
to copy a template sheet to the end of the workbook.
However, when running the following code in another module, the workbook seems to not recognize which sheet is the last sheet:
lastSh = ThisWorkbook.Worksheets.Count
....
ws.Cells(i,2).value = Worksheets(lastSh).Name
In some workbooks, the above code, as expected, returns the name of the last sheet (the newly created one).
In the workbooks with the odd behavior, lastSh points to the same sheet every time rather than recognizing I added another.
Another oddity: when I tried recreating the workbook by copying sheets from the erroring book to a new one, the error persists to that new version.
Why is the index of sheets seemingly stagnant or is my ".Copy after:=" doing something I don't know about?
Sub addToSummary()
Dim ws As Worksheet
Dim i, lastSh, lastRow As Long
Set ws = ThisWorkbook.Worksheets("Summary")
lastSh = ThisWorkbook.Worksheets.Count
lastRow = ws.Range("B6").End(xlDown).Row + 1
If ws.Cells(lastRow, 1).Value = "Total Amount Paid:" Then
Call addRow 'adds a row on a summary sheet if needed
ws.Cells(lastRow, 2).Value = Worksheets(lastSh).Name
Else
ws.Cells(lastRow, 2).Value = Worksheets(lastSh).Name
End If
ws.Cells(lastRow, 3).Formula = "='" + Worksheets(lastSh).Name + "'!currentPay"
End Sub
Regardless of creating a new file, this code is referencing the same sheet.

Answer 1

tempWs.Copy after:=ActiveWorkbook.Sheets(Worksheets.Count)
The number of sheets is not necessarily the same as the number of worksheets. If you have a chart sheet and 3 worksheets then Worksheets.Count is 3 but you have 4 Sheets so the sheet gets copied before the last sheet.
So you probably wanted this:
tempWs.Copy after:=ActiveWorkbook.WorkSheets(Worksheets.Count)