Having one dog in the home may make a dog picky(no competition to eat?) When I only had one dog I did let her 'free feed'....Clover was given a portion in the morning and she grazed when she wanted to throughout the day. She wasn't really food driven. Enter a puppy.....Clover decided it was not a good idea to leave her food or pup Onyx would get it. After having two dogs, I never free fed again and my dogs now are all good about eating when I dish it out. Kacie will take her food elsewhere to eat(I feed raw) she isn't one to eat her rmb's near her bowl so she eats outside and sometimes takes a 1/2 hour to eat, I have to remind her to eat. If she won't eat, I pick it up and fridge it, but seldom does that happen.
I trust her nose. If she won't eat it, it gets tossed.
I do the same thing, if my dogs won't eat something(fish usually) I do not force it on them