I am having the same issue described here: Charging bugs with new Orion XS 1400 and Pylontech RT12100 - probably due to DVCC - #8 by alexpescaru
I am using managed BMS-Can battery which reports current with high accuracy so this should be comparable to SmartShunt. And in my case installing additional SmartShunt to measure DC loads is also highly impractical as loads’ negative pole is connected to chassis in different parts of the vehicle so I would have to install multiple Shunts or run additional negative wire to all loads from common Shunt.