Find my friends can't see my location even though it's allowed to and my friends' miles away aren't showing up?

When I go in the find my friends app, it can't see my location even though I have it all set up to be able to see it. Also it stopped showing the distance my friends are away from me (probably because it can't see me for some reason). It shows me the address they are at but now the distance away. What can I do to resolve this? It's been happening for months. It's an iPhone 6.