Can't join my friends world and they can't join mine

If my friend is online I can't see them on my friends list most of the time even tho she is in my friendlist on the xbox application. But when I see her and want to join her world then it says the world can't load. And if I invite her to my world most of the time she can't join and if she do she keeps lagging out. Also the game doesn't start the first 6 tries.

 

Hope you can help me with this isseu because I downloaded it to play with my friends. But this is just a waste of my time and money.