It seems something is triggering the system to think all of the food has vanished, but only slightly. It happened in my last game, but I thought I had run out of food. This round I know that I have a ration chest full of food (maybe it was triggered when it filled to the top?). I got the "Food Shortage" warning in the events tracker, and the material tracker *summary* at right reads "2900 kcal" but when I open the drop-down for it, it does recognize the 68,000 kcal of Mush bars, 2900 kcal of Meal Lice, 4000 kcal of Muckroot, and 16000 kcal of Liceloaf.
It also seems that my dupe just retrieved lice to eat before food? Maybe related?