Make sure they get something in their stomachs at night…or early in the morning before they actually get up. My Talker did this for awhile and eventually it stopped when we figured that he had an empty stomach.
My dogs free feed and when I'm home with them 3 days out of the week, they very rarely eat during the day. They eat at night mostly and maybe snack around mid day the next day. All dogs are different so I suppose you have to watch each and every dog. But I noticed that if we fed them in the morning, they just don't eat so we stop feeding them in the morning b/c we were wasting a lot of food. Now we feed them 1 cup at night and what they don't eat at night, they will MAYBE snack during the day----but not much.