UNS-1K FMS SID/STAR
The lines do not show up on a SID/STAR if the track between the two waypoints is indeterminate; i.e. dependant upon turn radius vs groundspeed. However, with FMS/NAV engaged, the aircraft will navigate correctly between the waypoints.
Any "Straight-line" segment between two waypoints will be represented by a line.
Happy tracking....
'69