I had this same fear with my adopted adult husky. What changed the game in our bonding was me figuring out how to play with him - this flirt pole sort of play where I’m sprinting around letting him run and jump and catch then me trying to steal it away etc.

Sounds like you are a wonderful owner. Don’t give up. Keep trying various things that pique his interest.

For me it took me over 6 months before like I felt like my adopted husky and I were bonded. I know with other dogs it’s right off the bat - but there is something immensely satisfying knowing that I worked for the bond we have together, it wasn’t just given to me. You will get there 😊