Tread very carefully here, please. You do see your grandson, which is something many, many grandparents would envy.
To me this set-up sounds like one of two things. Either it is just the way the young live these days. They do not feel obliged to invite us, the elder generation, as we did feel obliged to invite our elders, and they do not see that we feel hurt, or dubious as to whether we should invite them, or invite ourselves to their place.
Much more worrying is the other possibility that comes to my mind; that your daughter is concealing something from you. Could she be ashamed to admit that money is so tight that she cannot afford to invite you to stay and eat?
Is she trying to hide that her husband/partner (is she living with anyone?) dislikes you, or that he drinks, or hits her?
One of the young women in my family will only meet me outside her home, obviously at times where her husband isn't home and isn't keeping tabs on her. I don't know why, and yes, it worries me, as I know of nothing we have done to give offence, so I may just be reading my own situation into yours, sorry.