Luxpower settings reset when adding a new battery

I recently had a hybrid solar system installed with a LuxPower hybrid inverter and two us3000c Pylontech batteries. I decided to purchase and add another us3000c Pylontech battery of exactly the same spec.

So I started by switching off the Isolator switch and also the switch on the inverter and disconnecting everything.  I then put the new battery in the top of the stack to make it the master. Connected the batteries in Parallel but left the power cables from the inverter and data cable unconnected.

So I had previously waiting for the current two batteries to be fully charged.  I then turned the batteries on in order from the Master to the last battery.  The batteries have an LED light which has 'RUN' underneath and a set of six light with an triangle underneath to indicate state of charge.  All six state of charge lights where full lit on the current batteries.

I then pressed the SW Run button on the new Master battery.  This new battery had two LED lights lit on the state of charge. The next LED light started to flash.  On the two current batteries each LED light on the RUN started to flash and on the new battery the RUN Led light was fully lit. So seems like it had started the balancing sucessfully.

I left it running over night. In the morning all the lights were out except the RUN led light on each battery including the new master battery was flashing, alternating between each battery. 

I then turned the batteries back off, reconnected everything. The positive power inverter cable to the Master's other positive connection and the negative inverter to the last battery on the negative connection. I then connected the data cable from the inverter to the rs485.  (The battery also had an option for CAN, which online videos seem to use. But since the inverter was originally connected to the rs485 port by the installers I added it back to the same one).

After switching everything on the battery LED lights remain unlit and the inverter asks 'Add a battery?'.  So my question is should I try to enter the settings on the inverter again or maybe try pressing the SW Run button on the master again with everything including the inverter connected. Or should I try the CAN connection instead of the rs485?  I didn't want to try anything else until I got some expert advice.

Many thanks in advance

James