<VChartIsland> uses <NuxtIsland> under the hood. When rendering an island component, the content of the island component is static, thus no JS is downloaded client-side. Since there is no JS, Provide / Inject does not work for <VChartIsland>, you need to use <VChartServer> which wraps <VChartIsland>.
Changing the island component props triggers a refetch of the island component to re-render ECharts again.
<VChartIsland> is used by VChart, VChartServer and VChartLight for Server-side Rendering.echarts.init's opts parameter. Injection key: INIT_OPTIONS_KEY.height and width property in init-options for SSR.setOption method. Read more here →.NuxtIsland fails to fetch the new island.