Here's a fix when running IL2 on higher than 100% desktop scaling (Display Settings, "Change the size of text, apps and other items")
Issue: The mouse pointer is either gone, or just clicks with an offset to the right and to the bottom. Very difficult to hit the button you want to hit ...
Fix: Change the properties of the 1946 desktop icon, switch on the 'Disable display scaling on high DPI settings'
(IL2 1946 4.12.2m, HFSX v7.03, on Windows 10, not checked/tested for other versions)