Its always been a random glitch, sometimes lag can just screw with how the food level can change. I did loose a giga on official due to this. Advice i found but never tried myself; prepare a ton of dodo kibble and use that to raise a giga. Really not sure how well that actually works as i never tried it. Now that I'm spoiled on unofficial and have the S+ Nanny, i never worry about babies dying. I know for some its OP and i sorta agree. But it also helps with this starving glitch, something i doubt wildcard will be figuring out any time soon.