A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
Found some kind of solution: AlwaysMouseWheel - portable program, adding 'Scroll Inactive Windows' function for older versions of Windows but can be used in Windows 10 to restore this functionality in Excel without uninstalling the latest updates, at least until Microsoft fix it (if they will...)
Update: Sorry, looks like AlwaysMouseWheel breaks scrolling in Windows 10 Apps like Mail or Calendar, so another similar program is WizMouse - less functionality but without that bug.