Sales team was not sufficiently informed.
Unfortunately, the function as a 2nd plotter on the Fly is not only possible via the network cable, as discussed when ordering. Afterwards, an additional NMEA 2000 cable had to be pulled with renewed effort in order to see the encoder data on the 2nd plotter. The sales team was obviously overwhelmed with this question and had to contact Garmin. The staff should receive better training on such issues. Still all stars, because everyone tried very hard and in the end everything worked as expected.