Using the ReactUnity/full-sample project, if I add an onChange handler to the Slider in pages/material/index.tsx:127, this console message never appears
<Slider onChange={(value) => console.log("Slider onChange value = “ + value)} allowScroll direction="horizontal" mode="normal" max={100} step={20}>{(val) => val * val}</Slider>
The same issue happens in my own project when using this component.