In regards to your latest reply; I would leave it down for about 15mins, and then take it up. Maybe offer it 2 hours later. They will learn after a couple of days to eat it when it's offered.
I used to free feed my dogs. I would put dog food in one bowl, puppy food in another. I would do this twice/day, once at 6 am and again at 7pm(before and after work). I did this until I caught onto the fact that Cody was eating Lilly's food and Lilly was eating Cody's food. Now, I put Cody in the kitchen with the baby gate up with his food, and leave Lilly in the living room with hers. Whatever isn't gone by 6:45 when I leave for work gets put up. The first 2 mornings neither of them ate a single bite. Then at 7pm, I would do the same thing, but only leave them for as long as it took me to cook dinner(15-30mins), and they both scarf their food down. The past 2 mornings they have been eating about 1/2 of their morning food. I expect they'll get better in time.