The inability of new users to @ other users is a spam prevention method. The limitation disappears very soon. It's a pain, but spam is a bigger pain.
I think @laurent or @tessus would be the ones to notify.
Also, if I'm not mistaken, even in Windows having the Automatically update the application option ticked doesn't actually automatically update the application. It should really say something like "Automatically check for updates" if I'm not mistaken. You always have to choose to update, at least in Windows. Are you actually having the updates happen without your approval in Linux?
