Draw Text on Chart

Hi All,

I am trying to use the Chart.Drawtext code to update the charts with signal information.  I am using:

 private void drawSignalPricesHighToChart(bool onStart)
        {
            if (onStart == false){
                var openTime = Bars.Last(0).OpenTime;
                var textHigh = Chart.DrawText("textSignalHigh", signalHigh.ToString(), openTime, signalHigh, Color.White);
                textHigh.VerticalAlignment = VerticalAlignment.Top;
                textHigh.HorizontalAlignment = HorizontalAlignment.Center;
            }else{
                var openTime = Bars.Last(0).OpenTime;                
                var textHigh = Chart.DrawText("textSignalHigh", signalHigh.ToString(), openTime, Bars.Last(1).High, Color.White);

                textHigh.VerticalAlignment = VerticalAlignment.Top;
                textHigh.HorizontalAlignment = HorizontalAlignment.Center;
            }
        }

        private void drawSignalPricesLowToChart(bool onStart)
        {
            if (onStart == false){
                var openTime = Bars.Last(0).OpenTime;
                var textLow = Chart.DrawText("textSignalLow", signalLow.ToString(), openTime, signalLow, Color.Orange);
                textLow.VerticalAlignment = VerticalAlignment.Bottom;
                textLow.HorizontalAlignment = HorizontalAlignment.Center;
            }else{
                var openTime = Bars.Last(0).OpenTime;
                var textLow = Chart.DrawText("textSignalLow", signalLow.ToString(), openTime, Bars.Last(1).Low, Color.Orange);                
                textLow.VerticalAlignment = VerticalAlignment.Bottom;
                textLow.HorizontalAlignment = HorizontalAlignment.Center;
            }
        }

I can get the text to appear in both backtest and the automate window of the chart, but not in the actual trading window,

Snip from a trading chart showing no text drawn.

Snip from the chart in automating which shows the text on the chart.

Can anyone explain why the text does not appear on the trading chart?  The code is in cAlgo, not cIndicator.

Thanks