no elevation/shadow on android only

Hello,

I have managed to get the shadows fine on iOS but cannot get the elevation prop to work at all on android, seemingly having tried every combination:

specifying in the styles.drawer prop of the Drawer
just having an elevation prop on the Drawer component
Specifying in the styles of the surrounding View of the drawer

Here is how it looks on both platforms: screen shot 2017-10-03 at 16 11 46

And here is the way I've arranged the styles:

const optionalDrawer = <View style={styles.cashpointDrawer}>
        <Drawer
            type={'overlay'}
            captureGestures={true}
            tapToClose={true}
            closedDrawerOffset={0.25}
            openDrawerOffset={0.2}
            styles={{drawer: styles.withdrawButtonOverlay}}
            side={'right'}
            acceptTap={true}
            negotiatePan={true}
            content={
              <TouchableHighlight underlayColor='white' onPress={invalidInput ? undefined : startWithdrawal}>
                  {withdrawOverlay}
              </TouchableHighlight>
              }>
            <TouchableOpacity onPress={invalidInput ? undefined : startNormal}>
              {button}
            </TouchableOpacity>

        </Drawer>
    </View>

withdrawButtonOverlay: {
    flex: 1,
    shadowOffset: {
      width: -5,
      height: 5
    },
    shadowColor: 'black',
    shadowOpacity: 0.5,
    elevation: 20
  }

Any help would be amazing!

Thanks

root-two / react-native-drawer

no elevation/shadow on android only #327