I see. After it happened 4 times in a row I inferred it was a typo. There seems to be problems with how planetary improvements and tile bonuses work as well. The behave very different than GalCiv III. In each case I have an uncontrolled growth on my home world that increments my negative food balance and doesn't seem to react to planetary improvements or techs in a clear purposeful way. I end up with low approval, a growth explosion and negative food production. Nothing seems to stop population growth.