VBA doesn't return where expected

I have a Summary workbook with a list of Data workbook filenames.
The objective is for the Summary workbook to open the Data workbooks one at a time and have them
1) Update their data or not
2) Run Solver iterations or not
3) Save
4) Close and Return

This has been working until it doesn't work. So, the reasons are a bit hard to track down.

Right now I'm working on the "Close and Return" part.
Here is the calling Summary workbook code (simplified a bit):

Sub Updater()
Range("D2").Select
   
    Dim cell        As Range
    Dim sFile       As String
    Dim flag        As Boolean

     Application.ScreenUpdating = False
' Cells in D2:count contain path.filename.xlsm list
    For Each cell In Range("D2", Cells(Rows.Count, "D").End(xlUp)).Cells
        
         sFile = cell.Value
         Workbooks.Open sFile
         ActiveWorkbook.Close SaveChanges:=True
		 
		 Do Until WorkbookIsOpen(sFile) = False
		 Loop
        
    Next cell

     Application.ScreenUpdating = True
     Application.EnableEvents = True

End Sub

What happens is this:
After the Workbook sFile is opened and all the steps it takes are done, it returns to the code above.
I would expect it to return to ActiveWorkbook.Close .....
But, instead it returns to Workbooks.Open sFile and, it appears, there is no value for sFile at that point.
And, the next step goes to the top of the code shown here and the same/first file is opened again.

Thanks...

OK. Here is a set of example workbooks that fail.
Open the Summary_Test Workbook and select the Update Macro EDIT and step through it..
When it switches to Data1.xlsm, you will have to switch back to the VBE.
You will see the Data1.xlsm variables now...
When the Data1.xlsm workbook is closed, the VBE will switch back to the Summary_Test Workbook and there will be NO variables shown and it will fail to properly loop.
If you comment out the workbook closing statement in Data1.xlsm, then the loop in Summary_Test.xlsm will work.

BUT, one way or another, Data1.xlsm and all the subsequent files have to be closed when they are done being run one at a time in sequence.

Thanks!

I'm not sure how to run the code from the summary workbook. The code in each of the data files is the same.
The data files are supposed to be dual purpose in the sense that they can be run on their own and all of their code pieces should be there for that purpose.
Then, in order to update all of the data files and summarize the results, the Summary file needs to control that process.
I suppose that there could be "identical" modules for each purpose. Modules in the data files that run from the data files and modules in the Summary file which run ON the data files... ?
What does the latter look like?

How about closing the data files from the Summary file? That seems to be an easy way around this issue.

Well, the typo was only in the latest code and not in the original that had problems. Your help was a big deal in getting on with this project!

Yes, it's working. The note about the typo was in the "edit" of my message at 10:45.