Open https://codesandbox.io/s/aloha-css-uyox7.
The app has an animating Box and "Hello" divs, however we got unexpected repaints over and over, and somehow the idle "hello" div also got repainted.
You can debug this issue by using Chrome Layers tab, you can see each element layering. You can enable flashing indicator by opening Chrome Rendering tab, and check "Paint flashing"