Gah, you are teaching him to turn his nose up by giving him all this attention when he does. The attention is rewarding and so the act of turning his nose up at his food has rewarding results which is why he's doing it. Dogs are even willing to go without food in order to manipulate their owners into fussing round them.
He ate the food fine for the first couple of days which proves that he doesn't dislike the taste and there is no reason why he should anyway. He just realised that when he ate it, you didn't pay him any attention and so he stopped again and now he has you fussing round him trying to get him to eat and he's loving it.

I suggest strongly to stop with the coaxing. He won't starve himself to death and he'll eat when he is hungry. I know it's hard but if you carry on with the coaxing, you'll get to the point where you can't get him to eat anything at all because he has learned to turn his nose up for attention or he'll become even faddier and refuse to eat a full balanced diet and then his health will suffer etc...
Faddy dogs tend to be over or underweight and they are made faddy by the reward from their owners of either all the extra attention or being offered tastier things that aren't generally as good for them as their proper food.

Put his food down without a word and leave it there for 5 minutes and then take it up and make him wait until his next meal time. Don't leave food down.
Even if he doesn't start eating it until after 4 and a half minutes, still take it up after 5. He'll learn to get in there and eat it more quickly if he's hungry before it's picked up.
Don't offer him anything else...just make sure there is always water available for him.

Once he realises that turning his nose up is not rewarding, he'll probably decide to start eating again on his own. No healthy dog will just starve itself to death. He's probably eating just enough to get by ok as dogs like him tend to and he'd probably eat more if you didn't spend so much time trying to get him to eat. It has the opposite effect.

If you are worried something else might be causing it, a check up at the vets is advised at least to put your mind at rest but, other than that, stick with one decent food and quit the coaxing, it is the worst thing you can do.