Lazy-loading amchart doesn't render on scroll down

Question

I'm using amcharts 4.9.31 in an Angular 10 app. I'm working on getting charts to 'lazy-load' on page scroll.
I have this setting set am4core.options.onlyShowOnViewport = true; Now the charts that are outside of the viewport do not load when they are scrolled into view. But they do when I resize the browser. How do I get the expected behavior, i.e. that the charts render when container is scrolled into view?