[Chartjs]-VueJs/ChartJs – single file component computed property only renders when I click the component in Vue Dev Tools

You have defined the method in a computed property but never used it.

Assuming you want to just get this running, load the chart on mounted:

mounted() {
  this.nutrientCharts();
},
methods: {
  nutrientCharts: function () {
    // your code here
  }
}