Or, is it a new bug?
* If it is not clear, I am a member for 12 months, but not for 1 year
You registered your account at oct 15. So you have to wait another 4 days for this badge.
The number of months is rounded up. But the year is an exact match.
And due to some distortions in the space time continuum, 12 months <= 1 year.