A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
Hello Steve,
Thank you for posting your query in Microsoft Office Community.
A quick question before proceeding:
Do you have multiple instance of Excel files open?
If the above is true, this is an expected behavior as Excel will only show the Average/ Sum/ Count result in the active Excel window.
As you're changing focus of the mouse by going to the workbook in second monitor, the result of the first monitor changes as it goes in active. There is no option to change this behavior.
Reply if you need further assistance and I'll be happy to help you.
Thank you.