Lots and lots of Havs can become picky eaters IF YOU LET THEM. The fastest way to make a picky eater is to cater to them or try to tempt them with different flavors, adding things to their diet, etc. Don't start something you don't want to keep up indefinitely!
With picky eaters, the best thing to do is decide on a good quality food. (Wellness is fine!) Put it down for him, and pick it up after 20-30 minutes WHETHER HE HAS EATEN OR NOT. Do not feed him again until his next regular meal time. (probably twice a day at his age?) He may skip a meal or two or three, but DON'T WORRY... a healthy dog will NOT starve himself. He'll just learn what the meal time rules are.
The other things you want to think about is how MUCH you are feeding him... From my experience, it seems like the amounts "suggested" by manufacturers are WAY on the high side. (probably in an attempt to get you to buy more) If you are over feeding him, that might cause him not to be hungry at his next meal. At 8 months, his growth may be slowing down, and he might not need quite as much food. Better a lean dog than a chubby one, from a health standpoint!
Also, make sure that you aren't sabotaging meal time with too many treats during the day. You will need training treats, but make sure they are good quality food, and factor that into what he's getting on a daily basis. Other than training treats, don't give him ANY "snacks" or you will only make meal time pickiness worse.
If you can arrange it, I have found with Kodi that the very best way to get him eating well is competition. When I go away, he stays with a friend who has several large dogs. They are all separated at meal time, so no one can actually take his food, but just knowing that there are other dogs around who are happily (and quickly) munching away who MIGHT take his food makes him gobble his up in no time flat. This effect lasts for a LONG time after he comes back home and has single dog status again.