I absolutely do not expect hugs from any of my four DGC, aged from eight to three. I savagely object to people assuming it’s ok for them to touch me, and even a handshake should not be taken as a right. No child should be expected to hug or kiss a grandparent, or sit on a lap, however welcomed it would be, physical displays of anffection should only be initiated by the child and if they don’t actually want to to touch, they shouldn’t be made to. Manners are different, though, and there’s no excuse for rudeness. Eye contact and a polite greeting, or thanks, really can be expected and the child (or indeed, adult GC) won’t hurt from a reminder to be polite.
OP you do give the impression that you’re needy and rather entitled. Back off a little, rise above what you see as attempts to upset you - you are the adult and can set an example in terms of grace and kindness in the face of adversity.