I am sure your grandson loves you.
What happened that his attitude change?
If he doesnt do it with anybody else, could it be something you only do?
For example, the hug - do you just go for the hug or ask for permission (very important for bodily independence)?
How often do you hug him?
I would try to avoid doing things you know that annoy him.
There is a big developmental leap between 4 and 5.
My kid went from super cuddly to "give me space".
From tons of kisses all day to a much lower number that I would like.
It is normal.