May just have been a rendering error, my guess is with OpenSeaMap (https://map.openseamap.org/?zoom=15&lat=-33.86182&lon=151.28148&mlat=-33.86444&mlon=151.28272&layers=BFTFFFFFFTF0FFFFFFFFFF)

However the lighthouse is in the correct position from what I can see (since the website grabs data from overpass it may have been displaying incorrectly in their browser)