FL MIDI Out plugin(s) instances do not require being routed/assigned to the mixer when using playlist Track Mode - which currently does not seem to account for this.
When using a MIDI Out in Instrument track mode, the wizard sets ...
If you drag a plugin into channel rack or double click it in plugin picker - new generator will be automatically selected.
If you create instrument track by dragging plugin from plugin database or plugin picker new generator won't be ...