3D Widget Color Transparancy Issue

I have a 3D widget containing a green progress bar placed into my scene. As I look around my level, the color of the progress bar continually changes transparency. If at any point I look directly at the progress bar, from then on the color is exactly correct no matter where I look. Here is a video: 2018-03-12 10-20-17.flv - Google Drive Any idea what could be going on?