I think "turning turtle" has scrambled some software in the BMS, resulting in the unwanted charging limitation of 85%. I would switch off, disconnect one terminal of the aux. battery, and wait (say) 20 minutes to give capacitance in the electronics time to discharge. Then reconnect, which will make the BMS reboot, and see if the problem has cleared. You will have to set the radio selections, etc, again.
The battery SOH looks good (100.3%) , based on your data, assuming yours is a nominal 27kWh battery.