The article below explains how the warranty procedure works for Victron.  It sounds to me like your meter is working but maybe not adjusted correctly.  There are all kinds of adjustments you can do to the meter to make sure it is getting a correct reset point and it is particularly essential that you do this when you have Lithium Batteries.  If you decide you want to do a warranty claim In your submission you would want to be able to demonstrate that you had done these.  Here is a link to my article about how to set up the meter to work with Victron Lithium Batteries and it includes the recommended parameters:  https://shop.pkys.com/lithium-installation-details.html  If you have different batteries then you may have different parameters. Victron also made their own video about how to adjust the parameters:  https://youtu.be/4ReljfO3k6M

If your BMV is not a Bluetooth model it might be better if you got a Bluetooth adapter to be able to adjust these settings more easily and share the data as screenshots with us. As part of the troubleshooting procedure you would want to be able to demonstrate if the raw data it was receiving was accurate.  The raw data is the voltage and the current.  Its easy to check if the voltage it is measuring is correct by using a digital voltmeter.  You need a more sophisticated meter to be able to measure the actual current flowing in the circuit but in the absence of that you can measure the voltage difference across the shunt which has a 50 mV drop when the current is 500 amps.  If the raw data measured is correct then the answer to your problem is in tweaking your settings. Note that in the instruction manual there is a way to zero out any small error in the zero current setting but before you do that you want to be sure there actually is zero current (by disconnecting all the loads)

We often get people who have installation errors and get wrong data as a result.  All the current flow in and out of the batteries must go through the shunt,  can you show me a photo of the battery installation that demonstrates that this has been set up correctly.

There are a lot of questions and answers in the online forum, here is a link for a search I did on BMV parameters.