Hello @bartplessers,
There is a bug in SystemJS library that is used in SharePoint on-premises, that is why the code doesn't work in a full screen mode. Please try this code, it should work in both panel and full screen:
fd.spRendered(function () {
var defineOrig = window.define;
window.define = null;
$.getScript('https://cdn.jsdelivr.net/npm/chart.js', function () {
window.define = defineOrig;
var Chart = window.Chart;
const ctx = document.getElementById('myChart');
new Chart(ctx, {
type: 'bar',
data: {
labels: ['Red', 'Blue', 'Yellow', 'Green', 'Purple', 'Orange'],
datasets: [
{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
borderWidth: 1,
},
],
},
options: {
scales: {
y: {
beginAtZero: true,
},
},
},
});
});
});