Whether they are sticky or soft, in both cases it most likely means the pecans didn't cook long enough to get the sugar mixture to a high enough temperature. This is another reason why making candied pecans in the oven is much better than on the stove! We can control the temperature and by following the bake time, we can ensure the pecans cook fully. Be sure to let the pecans cool as this will mean the sugary coating has hardened and won't be sticky.