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I don't confirm this. Are you using non-standard skin or other theming / shell enhancement programs? I just realized that the issue only presents itself if you go to Control Panel -> Display and turn on scaling. I run 125% since 1920x1080 on a 13" screen is a bit small. If I step it back down to 100%, then the icon shows up fine. I'm using the round Windows 7 (I think) logo meanwhile which seems to work fine with scaling enabled.
I'm not sure if this is a known bug or not (sorry if it is) but when you have configured the taskbar to use small icons (i.e. where the clock is only a single line), then the default start menu button disppears. Selecting an icon other than the Windows 8 logo fixes the issue but I'd prefer that icon over the other built-in ones. I'm using Windows 8.1 and the latest version here.