[InvientCharts] Missing tooltip

Hello
I’m trying to delevelop some application with InvientCharts.
I have to use chart with some dateTime series, of course I can’t use constant intervals.
My data source is set of pair date with value.
Almost everything is working fine - except tooltips.
In my chart I can only preview first and last tootip - others are inaccesible.
Last tool tip is available only when mouse is hoovered over first point, first tooltip is showing when mouse is hoovered over another points.
What I’m doing wrong ? Is it possible that is some bug in HighCharts ?
Source code is included below.
Whe I tried to add chart with constant interval - then tooltips are working fine.
Thanks for help, and sorry if that topic exist - i don’t found it.


    private void CreateExampleChart()
    {
        InvientChartsConfig config = new InvientChartsConfig();
        config.getGeneralChartConfig().setZoomType(ZoomType.X);
        config.getGeneralChartConfig().setSpacing(new Spacing());  
        config.getTitle().setText("Example of not working tool tip");
        DateTimeAxis xAxis = new DateTimeAxis(); 
        xAxis.setMaxZoom(60000);  
        LinkedHashSet<XAxis> xAxesSet = new LinkedHashSet<InvientChartsConfig.XAxis>();
        xAxesSet.add(xAxis);
        config.setXAxes(xAxesSet);
        NumberYAxis yAxis = new NumberYAxis();
        yAxis.setTitle(new AxisTitle("Wartość"));
        yAxis.setStartOnTick(true);
        LinkedHashSet<YAxis> yAxesSet = new LinkedHashSet<InvientChartsConfig.YAxis>();
        yAxesSet.add(yAxis);
        config.setYAxes(yAxesSet);
        config.getTooltip().setShared(true);
        config.getLegend().setEnabled(false);
        AreaConfig areaCfg = new AreaConfig();      
        DateTimeSeries dateTimeSeries = new DateTimeSeries("Value", SeriesType.LINE, areaCfg,true);
        dateTimeSeries.setSeriesPoints(getExampleRecords(dateTimeSeries));
        InvientCharts chart=new InvientCharts(config);
        chart.addSeries(dateTimeSeries);
        this.addComponent(chart);
    }
    
     private LinkedHashSet<DateTimePoint> getExampleRecords(Series series) {
        LinkedHashSet<DateTimePoint> points = new LinkedHashSet<DateTimePoint>();

        for (ExampleRecord dat : getExamples()) {
            points.add(new DateTimePoint(series,dat.getTime(), dat.getValue()));
        }
        return points;
    }
    
    private static class ExampleRecord
    {
        private Date time;
        private double value;

        public ExampleRecord(Date date,int iteratorValue)
        {
            value=iteratorValue*0.5;
            time=addMinute(date, -iteratorValue);
        }
        
        public Date getTime() {
            return time;
        }

        public void setTime(Date time) {
            this.time = time;
        }

        public double getValue() {
            return value;
        }

        public void setValue(double value) {
            this.value = value;
        }
    }
    private static Date addMinute(Date dat,int minute)
    {
        Calendar cal = Calendar.getInstance();
        cal.setTime(dat);
        cal.add(Calendar.MINUTE, minute);
        return cal.getTime();
    }
    private static List<ExampleRecord> getExamples()
    {
        Date startDate=new Date();
        List<ExampleRecord> result=new ArrayList<ExampleRecord>();
        for(int i=0;i<20;i++)
        {
           result.add(new ExampleRecord(startDate, i));            
        }
        
        return result;
    }