I had exactly the same problem, exactly in the same context.
Thanks to @Wobbleyheadedbob for hinting Find Option Index. [ATTACH=JSON]{“alt”:“ComboBox: From string to Enum”,“data-align”:“none”,“data-size”:“full”,“data-tempid”:“temp_164599_1557942614516_64”,“title”:“checkpoints.PNG”,“caption”:“ComboBox: From string to Enum”}[/ATTACH]