Shunt, BMV-712, venus-os reading more amps used then reality

My Victron shunt, with the BMV-712 smart, shows more recorded amperes than reality. The BMV-712 smart is connected from the shunt with an RJ12 UTP cable, and from the BMV-712 with a Ve-Direct / USB cable to a Raspberry Pi with Venus-OS. on the monitor it shows more power consumption than in reality. this is also the case with the 230V amperes from the quattro inverter. eg: reality 0.6A consumption, and on the Venus-os it says 1.2A.

The 24 Volt system: actually 10A, and on the Venus-Os almost 20A

The shunt is connected from my lifepo4 batteries minus cable and then to a central mass busbar. There are no other masses connected to the lifepo4 batteries.

I measured the actual recorded amperes with a professional ampere meter/clamp.

The story becomes even more exciting when we go sailing. from the alternator two buck boost dc-dc converters 50A are connected in parallel. the ground also goes to the central ground busbar and the plus goes to the plus of the lifepo4 batteries. My 1580Wp solar panels with two Victron MPPT chargers are also connected to this in parallel.

As soon as the buck converters start charging, the amperes bounce from plus 30 TO minus 200A while the lifepo4 batteries are properly charged according to the Bluetooth app of the lifepo4 batteries.

As a result, I cannot determine how full/empty the lifepo4 batteries actually are according to the shunt and venus-os monitor. I am well informed in terms of electrical engineering, but I cannot solve this.

Translated from Dutch by Google.

One thing to check is on the BMV using VictronConnect app in your phone, under Settings, Misc are the shunt amps and voltage ratings correct. If you have a 500A shunt and for some reason 1000A is chosen it will read double amps.

Why the amps are fluctuating when sailing may be another issue due to electrical interference or loose connections vibrating. Check everything is securely plugged in and cables supported. If it is data transmission then the phone app and GX device will not agree.

Secondly, are the amps in Victron Connect the same as the amps reported on the GX device.

Thanks for your quick response.
Good questions.
The shunt is 500A and also in the victron connect app.
The reading amps are the same in the victron connect app and on the venus-os.(only for the 24V board system. i can’t check the 230V side other that my amp clamp meter witch has the different reading.
I have checkt all connection and can’t find anyone who is not properly connected.
i’ll would try to use another shunt for testing, but dont thinks that will solves this.