Hi @Glyn _ QRMS ,
Did this problem appear in all Excel Workbooks?
Where did you save the Workbook?
I suggest you try to create a new Workbook in local desktop with simple formulas, and check it this problem is still existed.
Then go to File- Options- Advanced- Scroll down to the Formula and choose the Manual option, enter 1 in the Manual box, and click the OK button:
You can provide the formula you're using here, this problem may related to the incorrect formula.
Just checking in to see if the information was helpful. Please let us know if you would like further assistance.
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