Hi there. Thought I'd chime in here. I don't know anything about babies Jack's age but have 3 ekkies. You have only had him since October? That is not very long. In my experience ekkies can take awhile to adjust to new surroundings and some are just naturally more wary of things. One of my guys, Mr. Spock is curious about everything and everybody. Tigger on the other hand is very reserved and prefers to sit back and observe instead of jump on your head and check you out like Spock.
You've received some good advice about feeding. I'm so sad that the breeder said to swap him out!! With that kind of policy, he could bounce from person to person or I'd fear that he'll end up in a breeder cage
I hope you will give yourself and Jacks some more time! As long as you're keeping his weight normal/steady, he will be fine and will come around. Tigger took MONTHS to trust me - and granted, came from a bad situation - but he just needed time and now he's a velcro bird!
But back to food - one of my passions when it comes to my boys - you're doing great offering foods in different ways to see what he likes. My 3 are surprisingly all different with their favorites, both type and presentation (chopped, pureed, big chunks, shredded, etc)! The one trick at my house that is almost fail-proof is to act like I'M eating whatever I want them to try - they want what's on MY plate! Lots of "yums" and drama over how good it is gets them interested! They are flock creatures and Jacks is looking to you to learn what is good and bad so give that a try. Sit near him with a salad that has all safe stuff for him. Show him pieces of cucumber or whatever, take a bite and ooh and ah over it. Sounds silly but it works here!! The other thing that always goes well here is to have them in the kitchen with me on a portable perch. They'll try almost anything I offer in that situation. I realize Jacks isn't ready for that yet but something to keep in mind for later.
You can also puree veggies into a spread, so to speak. Warm it a little so it resembles hand feeding formula - or even mix formula with it. That would be familiar to him and you might have luck there introducing new flavors. You can try that on a bit of cracker if he likes crunchy things. Any mashed veg with a little seed sprinkled on it to entice him is good. And just keep trying different presentations - big chop, tiny chop, shredded, mashed, matchstick style, whole on a skewer, a leafy green woven through cage bars, raw, cooked, steamed, etc, etc. Be creative and keep trying. They are stinkers. A shredded carrot might get ignored one day but gobbled up the next!
On the subject of trust and building a relationship - don't stress. They can sense that! Spend some time sitting on the floor near his cage and leave his door open. Read to him, sing, sit quietly and crochet or whatever, play with something he might find interesting, etc. and let him come to you at his own speed. I promise you once he gets over that initial hurdle, it's all downhill. Maybe the breeder was rough with him, maybe they did something that scared him. Who knows. I DO know they are good at holding grudges! LOL If you can or have already ruled out health issues that may be contributing to his behavior, then settle in with some patience and know that you're doing what's right for him. Positive reinforcement and giving him choices (and making the "right" choice irresistible
) is so important!
Keep us posted!!