Baby not bonding with older sibling

I have a now 1 year old and an almost 4 year old. My oldest has been getting more interested in her little sister and tries to play with her and make her laugh but my youngest just wants nothing to do with her. She’ll smile and laugh at me and my husband and then our daughter will come over and try to the do the same thing we were doing and she just gets serious or crawls away. It breaks my heart because I want her to give those smiles and laughs to my daughter too. My daughter doesn’t play exactly like us with her, shes a little more silly and loud, not as clear if that makes sense. I’m just curious if anyone has this experience? I’ve only ever seen the older sibling not bonding with the baby, but this time it’s the opposite.