tooltip is not visible in range slider

I tried to set up the range slider with tooltip as follows,

<Range
        name="value"
        min={0}
        max={20}
        defaultValue={sliderValues}
        tipFormatter={(value) => <span className="tooltip">{value}</span>}
  />

In the console, it shows the following error,

Warning: findDOMNode is deprecated in StrictMode. findDOMNode was passed an instance of Handle which is inside StrictMode. Instead, add a ref directly to the element you want to reference. Learn more about using refs safely here: https://fb.me/react-strict-mode-find-node
    in div (created by Handle)
    in Handle (created by ComponentEnhancer(Range))
    in div (created by ComponentEnhancer(Range))
    in ComponentEnhancer(Range) (at Slider.js:22)
    in ValueSlider (at Hazard.js:15)
    in div (at Hazard.js:12)
    in Hazard (at PrivateRoute.js:16)
    in Route (at PrivateRoute.js:8)
    in PrivateRoute (created by ConnectFunction)
    in ConnectFunction (at App.js:64)
    in Switch (at App.js:48)
    in Router (created by BrowserRouter)
    in BrowserRouter (at App.js:46)
    in Provider (at App.js:45)
    in App (at src/index.js:8)
    in StrictMode (at src/index.js:7)

But my tooltip is not visible. am I missing something?

Start by reproducing the Range example with tipFormatter under React StrictMode, then inspect the Range and Handle entry points shown in the warning and the usage at Slider.js:22. Determine whether the tooltip is rendered and whether the findDOMNode warning affects its visibility; done means the supplied tooltip appears without the reported failure.