Empty SVG tags when using renderToString() for the first time

I render a component including icons (with mode svg) to html code to be shown in eBay descriptions:

import { renderToString } from '@vue/server-renderer';
import { MyComponent } from '#components';

onMounted(async () => {
  await renderToString(
    h(MyComponent, {
      prop1: 'hello',
    }),
  );
})

Since I updated to 1.4.x the icons are not working anymore. The svg tags are just empty.

I tried out a lot and found out that the svg tags are just empty on first call of renderToString(). But they are visible when one of this conditions is true:

• When changing something on the page and Nuxt is refreshing (without refreshing the browser window)
• If I call it twice with a little delay between the icons are working correctly
• If I have the same icon visible on the page already

Start by reproducing the first-call behavior around the renderToString() entry point described in the issue, comparing it with a delayed second call and an icon already visible on the page. Done means the initial renderToString() call produces populated SVG tags for the component's icons, with the existing reproduction conditions covered by tests.