Element with elevation doesn't get overlayed by the drawer

[agharium]

That tab has an elevation property of 3.

And this was happening:

I managed to solve that by applying elevation 3 to the upper part of the drawer:

But now there's still a part of the tab that doesn't get covered by the drawer mask.

Any ideas?

This is my render:

render () {
  return (
    <Drawer
      ref={(comp) => {this.drawer = comp;}}
      style={styles.container}
      drawerWidth={width*0.8}
      leftDrawerContent={<Menu/>}
      type={Drawer.types.Overlay}
      easingFunc={Easing.ease}
      onDrawerOpen={() => {this.setState({drawerIsOpen: true})}}
      onDrawerClose={() => {this.setState({drawerIsOpen: false})}}
    >
      <Tab 
        onPress={() => {this.drawer.openLeftDrawer()}} 
        title="Pró-Mamá"
      />
      <Main />
    </Drawer>
  )
}