With the release of BS3, Brad has put in a limit on the maximum ABV based upon the tolerance of the yeast strain used. If no yeast is selected, it will default to using 10%. High gravity yeasts will be reflected by their tolerance as given by the yeast companies with a higher value.
It can be worked around by editing the yeast and changing the max % alcohol tolerance for the yeast, but don't then be surprised that you don't reach a higher value if you have exceeded the published tolerance.
This change was outlined in the release notes Brad published on his blog for the new features in BS3.