WFCO had some quality problems when they first got into RV systems back around 2004, but they seem to have improved. Still, a converter failure on a 2016 is not much of a recommendation for them (if it is indeed a failure).
The 8900 series is an integrated 120v and 12v power center, providing 120vac circuit breakers, 12v power conversion and fuses, plus battery charging. Is it only battery charging that is not working? When on shore power, the converter function should be supplying all your 12v needs in addition to charging the battery.
Before you go too far down the road to replacement, are you sure you have 120v power into the converter/charger? Did you check the reverse polarity fuses to make sure neither is blown? And the physical connections to the battery?
You can get replacement circuit boards for the WFCO if needed, but on a 2016 I would first contact WFCO about the possibility of a warranty replacement.