Give him time to get settled, everything is new for him. I totally understand that you needed to move things to make it safer for him, but if everything is safe now I wouldn't move things around again for a few days or even longer if you can manage that. - re the metal bars, is it possible to spiral cardboard tubes around them? i saw someone else do that on their detolf cage. Do you have anything else you can place in front of the wooden part i.e. a chewable mat or chew toy such as those big woven carrots you can get or even just some cardboard etc.
You may have to be patient with your hamster and give him time not to be scared of you, try and not take it personally, everything is new for him. He is only tiny, I always look at it like we must seem like giants to them or a gorg to their fraggle (google it if you have no idea what I am on about
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Congratulations on getting a new hamster, I hope he settles in soon for you.