Custom Marker keeps flickering on every render

I’m trying to set up a slider with a custom marker that moves with a an updating value. But every time a render is called the Custom marker flickers and makes it hard to grab. If I remove the custom marker the standard marker works perfectly, no flickering and easy to grab.

Here is my slider:

<Multislider
  customMarker={() => <Image source={scrubber}/>}
  sliderLength={Dimensions.get('window').width - 40}
  touchDimensions={{width: 50, height: 50}}
  values={[Math.round(slowRacer.currentIndex || 0)]}/>