Forum Discussion
Application.ScreenUpdating
Yes, I see where you are going but as the two open workbooks are in the same instance and active within their own window environment the application property should still be effective on the primary display.
It does state: "all of the Excel application-level window methods, events, and properties remain unaffected and work the way they have in previous versions of Excel", so this implies 'ScreenUpdating' should be the same.
I still don't understand why Microsoft have not answered this question considering the number of references that can be seen just by putting this inquiry into a web browser. Plus, what are all those Excel application developers using 'ScreenUpdating' doing when used in 2013/2016?
Someone has reported this problem to Microsoft in the Excel’s suggestion box.
Please check it https://excel.uservoice.com/forums/304921-excel-for-windows-desktop-application/suggestions/18688627-vba-screenupdating-property-does-not-work-in-excel and vote for it as I did.