I think that every Yorkie has a different personality. My 4 month old furbaby TJ is the laziest thing ever. He sleeps most of the day away in my lap. My 10 month old Yorkie Riley on the other hand is very rambunctious. At first, we though there might be something wrong with Little T (TJ) but he was checked by a vet and he is perfectly healthy. If I were you, I would schedule a vet check-up just in case. It will reassure you that nothing is wrong with Bunker, and it will give you a chance to get acquainted to your vet. Hope everything goes well. Good luck with Bunker!
Post pictures soon!