How to fix iPhone location issues in Find My app?

Hallo,

I allowed an iphone user to see my location and vice versa. while it works with others I can't see his location and he can't see mine. In both "Find My" apps it says the other can see ones location, but it won't show it.

any ideas on how to solve this?

[Re-Titled by Moderator]

Original Title: Iphone won‘t show a certain iphones location on „find my“