Current fluctuation on Charge or Discharge

Hi All,
I am setting up a battery pack with 16 cells LiFe cells and am using a Chargery BMS. The cells are 3.3v 100A in series. My issue is the current sensing is unstable with the charge or discharge current cycling up and down.If the discharge current is 65 A the the discharge current will cycle from -30A to -120A. I have tried calibrating the current shunt and have also tried resistors in line of varying resistance from 50 Ohm to 20 K Ohm. This cycle makes it difficult to determine accuracy and also the reported SOC is not correct.
The system is connected to a solar inverter and not a dedicated charger. Any tips please as im going nuts with this one.

More information is needed to be much help.
Start looking for help at place of purchase. I’m losing interest in supporting Chargery, as they often sell direct at less than my cost.

They will need to know shunt size, length & routing of sense lead, and inverter frequency to start.
They could also send a known working unit to test.