Royal Canin Puppy Food ???

I have had real fussy issues trying to get Bijou, now 16 wks. To eat puppy food. He got sick with vomitting unknown reason, and vet had him on chicken and rice. He only ate that for a day in a half, tried pasta, didn't want that. He ate Wellness for first 4 wks and now won't touch it. Tried dry, wet with can, and with a couple Stella nuggets crumbled, no go. He would go hrs and hrs not eating. My cats were supper fussy and will eat Royal Canin and have done really well on it. I always thought Royal Canin was a good food so I got a small bag of puppy and Bijou loves that with a splash of water and 2 Stella nuggets.

I have now done more research on Royal and have found it is not a good food. Now I don't know what to try. I have already tried 4 diff dry foods, 3 diff cans, sweet potato, cottage cheese, tons of stuff. I have jumped through hoops!

Does anyone know of a puppy dry food that is real small like the Royal Canin puppy food? Bijou seems to really like the tiny bits. And which one seems to have really good flavor that puppy's often need to get them to eat it. Any advice would be so appreciated. I find most puppy foods say for any breed, but I think it is important to be taylored to breed size. Bijou isn't even 6 lbs yet. Thanks so much