So thats called resource guarding! It most commonly comes from a perceived threat to resources (toys, food, treats, water even sometimes, occasionally affection or one specific person too) Id suggest tryna a set up where they can be fed in the same room, just like separate corners with either like a gate or x pen to separate or human to supervise them when there’s active eating happening! Resource guarding around food can often be quelled with just verbal redirection and guidance / reassurance, like them knowing you’re keeping tabs on the situation can help take away the need to be on guard as much in the dogs brain that’s is
Certain medical conditions, such as pain or anxiety, can contribute to food aggression. I would consult a vet and make sure that there are no medical conditions going on. After that I would consult with a dog behavioralist. Something has happened to cause this behavior and it could be things that seem less obvious to us if it's not medical. I completely agree with you that this is putting everyone in the potential for a dangerous situation.