When I post exactly the sam edata to example here: https://codepen.io/DanEnglishby/pen/dqyyzp
it shows the chart.
In SQ the chart is empty, but the values are there - they are visible on mouse over - see screenshot.
Maybe outdated chartjs library?
Once I specify the this.chart.pointRadius = 1; I can see the chart plot.
Maybe you may want to add a default value of 1 to the chart radius.