After transitioning from NX1953 to NX2206, creating a Feature Control Frame the option to change the Characteristic symbols are not available in the FCF dialog as they were in NX1953.
Starting in NX2206 the Feature Control Frame dialog has been simplified to make it smaller, after placing the FCF on the drawing the FCF options will be available from the ribbon.
If the ribbon is minimized the FCF Options will not display, so make sure the Ribbon is Expanded.