ScreenUpdating not working with multiple workbooks

Hello,

From a macro in VBA, I need to manage multiple Excel workbooks.
To avoid having screens "flickering" when opening x files, I disable screen updating with "Application.ScreenUpdating = False".
With Excel 2016, this code no longer works, since each workbook has its own Excel application (The same issue with "Application.DisplayAlerts" which still shows messages from other workbooks).
How can I work around this?
Is there a way to open multiple workbooks in a single instance or to disable screen display for all open workbooks?

Thank you