the UMG hovers actor will disappear when it out of viewport

I make a UMG HP bar hover the MonsterCharcter.
But when I turn the camera and make the monster out of the view port,and turn back again,the UMG disappear.
what’s the problem?

85768-notwork.png

Don’t use “widget” ,use “widget component”,and update the component rotaion face to you in the tick event.