Excel 2016 - Missing Excel work with no explanation (no crash, etc.). WHAT HAPPENED?

[LisaDavis]

First, let me start by saying for thelast 10 years I have worked primarily in Excel. I have literally spentthousands of hours in Excel and never had anything like this happen before...
Yesterday, I was working in Excel and had 3 files open. I was no longer using file A so I wanted to save and close it, but there were a couple circular references in there. I fixed those errors, updated all open workbooks (F9), and confirmed there were no more circular references. When I switched back to files B and C, where I had been working for the last hour and a half or so, I immediately noticed about 20 or 30 minutes of work was missing.
Please note:

• I use autosave - every 4 minutes
• The files did not crash, glitch, stall out, or in any way give any indication that there had been a problem
• The file did not revert to the last time it was saved, and I did not lose all my work
• I could pin point the point at which it stepped back to because there were a couple cells on a tab with data that I had not entered. I had made a change in a particular cell from 0 to 4, and it (and oneor two cells in columns to the right) but it had been updated to something like 986,XXX. Everything before I changed the cell from 0 to 4 was still in the file, and everything from that point forward was gone -- as if it never existed
• The missing work was across multiple tabs and in two different workbooks
• No tabs were deleted (still in the file with all work done before X point in time), but everything I had added or changed was gone
• There were no actions to step back/undo

I have never seen work disappear in an instant like this. I have lost data tons of times due to crashes or files locking up, but other than the fact that I was missing some work, I couldn't even tell that there had been an issue.
I checked my RAM (showing 8GB installed at the time) and confirmed with IT this morning that my laptop only has 8 GB of RAM - so none is missing. The IT Tech manager had never seen anything like this either and suggested it might have been something outside Excel (such as a Microsoft system update running in the background) that caused the issue.
His only solution is that if it happens again, they will have to build me another machine, but I would really like to know what happened. Have any of you experienced anything similar or ever heard of this? Any ideas what happened?

 

[gmittar]

Do you have code in any of the files?

 

[LisaDavis]

Of all 3 files, the only code I have is on one tab of onefile. This is the one file where I was not missing updated data/work.

Sub UnhideAll()
Columns.EntireColumn.Hidden = False
Rows.EntireRow.Hidden = False
End Sub

Sub HideRows()
Dim cell As Range
For Each cell InRange("A2:A61")
If NotIsEmpty(cell) Then
Ifcell.Value = 0 Then
cell.EntireRow.Hidden= True
End If
End If
Next
End Sub


Sub HideZeroColumns()
Dim cell As Range
For Each cellIn Range("B1:BS1")
Ifcell.Value = 0 Then
cell.EntireColumn.Hidden = True
Else
Ifcell.Value = "" Then
cell.EntireColumn.Hidden = True
Else
cell.EntireColumn.Hidden = False
End If
End If
Next
End Sub