What is the reason a UMG combo box in an animated canvas would not show text

We have two combo boxes in a canvas panel that slides into view. When that panel slides into view, the text of the combo boxes is not visible. I can see the text in UMG when not playing so I know its not a font size or ZOrder issue. I just see an empty combo box that I can click on that has no text. Any ideas?

Thanks!

If I scrub the animation manually, I can actually see the text disappear when it moves. The text is not keyed in the animation, so perhaps this is a bug with the combo box?