We have a custom set of "Stages" in the Stage attribute. One of the values does not show in the UI once selected.
It is actually there as you can filter on it and find the related projects, but it is blank in the UI.
This appears to be caused by a extra character in the lookup id which was causing the value to be blank in the UI.
Release : 15.9.3
Component : CLARITY STUDIO
Compare the length of the attribute and it showed an additional character.
This value was deactivated and a new one created.