They just released new software last night. I hope this helps. I have the 899 also, install tomorrow and fish for the weekend.
v_7.020 - 859ci HD, 859ci HD DI and 899ci HD SI
General Fixes
Removes NMEA0183 functionality when i-Pilot® Link™ is connected
Corrects issues caused when Follow the Contour feature used on an i-Pilot Link while recording an iTrack and AutoPilot is turned on.
Corrects issue to delete iTracks from all units on the network
Corrects POS mode allowing Chart/Side Combo view to be seen on SI units
New Features
Adds support for AutoChart PC and ZeroLine Map cards
Adds sonar sharing features for the 899ci HD SI. The transducer on the network can be shared with a non SI (X)X59ci HD (2014) product through the Network Source Set Up Adv. tab. It also allows SI units to utilize to dedicated DI. Both units must have software version 6.900 or higher. This feature will have a staggered release between now and the end of the Summer for select older models.
Adds Navionics Platinum+ compatibility