A choice field dropdown list supposed to show the Label of choices. However, when the choice field is been viewed from a popup window opened from a reference field icon, its drop-down items are the value of choices instead of its labels.
Istanbul, Jakarta, Kingston
The choice type field dictionary has the field 'Choice' = --none--
Hypothesis: the conditions necessary to reproduce this behavior may be found on old fields because, in the latest releases such as Istanbul and latest families, the option --none-- cannot be saved for a field of Type=Choice.