SOC problem

hello, I have a problem in the interface of the bq studio. After calibrating the bms my battery has a charge level of 30%. 
I start to do a load test and then strangely the SOC goes to a completely false value of about 7% so to remedy this problem I do a reset. 
after the reset I have the correct SOC value then afterwards I must unlock the battery executing an unseal then the SOC value becomes false again in error 
and the EDV2 bit turns red. I don't understand how to get the right SOC value all the time.