IntelliSense doesn't understand Unreal macros and functions. Visual Assist does.
Visual Assist adds Unreal Engine–aware IntelliSense, navigation, and refactoring to Visual Studio — accurate on UCLASS, UFUNCTION, and other UE macros where the built-in parser breaks.
Try a fully functional trial of Visual Assist for 30 days. No reinstallation or reconfiguration is required if you purchase.