MJS

Well, there is this saying: never change a working system. So if nothing really bothers you I would not change anything.
A few things were bothering me i.e. the 2A current the machine was drawing from the grid and one couldn't turn it off. So I went and upgraded (in steps) U1 to 71.95 and U2 to 02.60 what I found being the best combination for me and my machine (exactly the same as you have). I use solpiplog on a raspberry pi to monitor and control the inverter. That works fine for me and a lot of issues are solved but what hasn't been solved is that the inverter is not SOC controlled but voltage controlled. Apparently this can be overcome with solpiplog but I haven't been able to verify it.
Last not least the BMS works fine with the inverter. Especially the charge current setting and the do not charge command. On the other hand the charge voltages are 53.2V for bulk and float. There are opinions that this is too high although Pylontech confirms this being right. So if you think these voltages should be lower you must not use the PYL option because it forces the voltages to 53.2V.
 

My distributor provides 90.xx for the OG-7.2 firmware. Currently 90.28.
The units were on 4x.xx version when shipped.
 

Yes, your cable or settings is incorrect, just change setting 05 back to USE until you can resolve the cable setup.

For those who still struggle, received a mail from Pylontech:
1.
inverter pin: RS485B——3, RS485A——5
battery pin: RS485B——8, RS485A——7
2.
Connect to Master battery RS485 port,
RS485 baud rate 9600
the ADD setting for baud rate 9600 shall be “1000” (default is “0000) (master battery)
3.
section reference numbers from the 05 - battery type: “USE” or “PYL” (have to be PYL in my opinion)
4.
set low dc cut-off voltage: 47,5v or 48v (won’t matter if the communication works as 02, 12, 13, 26, 27, 29 become self regulated by the batteries)
5.
after turning off the inverter manually, all batteries shall be shut down and restarted
The above is for the Axpert VMIII / KING 48V/5KW inverters.

The battery icon flashes when there is successful communication  between the inverter and battery.