03 Battery voltage is too high, is the unit connected to the BMS in the batteries? the type of battery needs to be changed depending if the BMS are connected or not. Also, the QTY of batteries needs to be set.
Just a thought, have you a decent size DC cable going from each battery to the Multi. At high amperage, small cables have a large voltage drop.
I would have a set of 2 cables going direct from the multi going to each battery, I would not daisy chain the batteries together.
I don't think it is suitable, It will add a loss and could generate heat, Yes in your system you are going to run 6 sets but it would be better to run 2 groups of 3 sets so you can take 1 group offline for maintenance at any time and still keep working. 250 Amps may be initially higher.
You need...
I have been contemplating the same for 100Ah 48V system with 5k inverter, The charge current is 100 Amps so you basically need a 200A BMS. I finally decided to give this one a go. https://www.aliexpress.com/item/1005001292579677.html?spm=a2g0s.9042311.0.0.14974c4dc28wBz