I also had instability with the system shutting down. The communications between the battery and inverter is a hoax - it does not work. I set the voltages up under USER and no more problems. 54V with 48V shutdown or 27V with 24V shutdown. No communication cables anywhere. Batteries charge fine - they have internal BMS.
Even with Kodak and Pylontech I had issues with the communication. Just set up under USER and the systems work fine.