If it's a BMS issue it will take out the same group again.
If you have access to the balancing resistors (assuming a balancing BMS, and assuming it's resistive shunting type), then when you connect up the new cells to it, and you know that the new cells are below the balancing voltage, connect a multimeter set to 20VDC or less with one probe on each end of that cell group's balancing resistor (often a black rectangle with silver ends marked 101 or similar, in a row of identical parts, one for each cell group).
Any balancer taht is on will have a voltage across it generated by the current thru it. Any balancer that is off will not.