Both of those functions are being hit. What are the key properties of the return value from the FSceneViewport version should I be looking for? the FReply it is returning has the following properties:
MouseCaptor and JoystickCaptor set to the SViewport
EventHandler, FocusRecipient set to null
bIsHandled 1
bReleaseMouseCapture 0
bReleaseJoystickCapture 0
bAllJoysticks 1
bShouldReleaseMouseLock 0
bUseHighPrecisionMouse 1
bPreventThrottling 0
bEndDragDrop 0
FocusChangeReason SetDirectly