Set position in viewport not working

I have a shoot widget button that contains a border (which I need because I want to be able to move the camera with touch while holding the button, normal buttons not allow this) and I want this widget to follow the user finger when holding the button. I’m using the OnMouseMove and get the screenSpaceLocation to get the location of the finger to get the finger position and then I’m calling the set position in viewport and is not working in ue5.1