DD doesn't like her grandad 😫

So my dad is by far the most devoted grandparent ever, he is smitten with my daughter who is now 11weeks old. When she first started smiling properly she used to smile at him all the time when he made noises and pulled faces. All of a sudden over the past week she screams bloody murder whenever he holds her or looks at her. It's not like she doesn't see him enough he comes round atleast every other night and we generally spend every Saturday with them all day. It's upsetting me because I want her to love him like he loves her. He's the person I wanted to babysit for the first time and I don't know how to get her to like him again. She did go through a phase where she didn't like anyone but me but now it's just him she hates!!! Help please!!