When the yellow curve in the XOLTA app is above 0, it means that your solar panels are producing energy. If this happens at night, there has likely been an error during the installation and commissioning of your battery system. The same applies if the black curve is above 0 when the sun is shining, as this indicates that you are purchasing electricity in sunny weather.
If you experience this, please contact ServiceX support at support@servicex.dk or by calling +45 35 153 123, followed by 2.