Wrong measurement of current on Batrium shunt

Since a few days I have in my system extraordinary values of current in charge and discharge. The values from the Batrium shunt goes from -1200A to + 2000A within in only minutes.
Current Limit is 300A. The values are from the Victron VRM reported.
The SOC jumps due to that up and down.
Are there similar cases somewhere. May it’s an voltage overly from somewhere in the line?