A question about the trigger of OnTouchMoved

Hello, I’m new to UE4. I was wondering if OnTouchMoved had bug?

At the same time, I am using axis mapping and use mouse for touch.

However, when I click the screen with the mouse, OnTouchStarted can work well, and OnTouchMoved is not working, so does OnTouchEnded.

Is this a bug? Or is touch event consumed by something?

Look forward to your reply. Thanks everyone in advance!