I hit the feed button, feed him until it's full that means 100%, but it won't stay, when I go back to the helminth screen it reverts to 10%. There is absolutely no other way to get to the feed screen, and if you had to get to that screen in only one special way, and not another, it would still be a bug. I really don't understand your logic. Should you not be able to feed it by the IDK "feed" mechanic?