Today I've updated my 2011 15" MacBook Pro to macOS Sierra. After everything got updated, I've entered the Mac App Store in order to download Xcode. I saw in the "Apps Made by Apple" section the macOS Sierra, which seemed weird to be shown as downloadable, since I've already downloaded and installed it on my MacBook. I thought maybe it's a minor update, so I clicked on Download button.
Since then, it is downloading the full macOS Sierra. The problem is that I can't stop it. I don't see it in the Purchases tab and on the button where it said Download earlier, it's says now "Downloading". When I press on the option key to cancel the download nothing happens.
Can you please help me to stop the macOS Sierra download? It is slowing the whole Wi-Fi...