I was having this problem and I figured out a fix for me. I was sharing with two people (A and B), and when I got the new iPhone, I wasn’t able to see Friend A’s location even the though they could see mine. Then Friend B also got a new iPhone and they couldn’t see mine, even though I could see theirs. In messages it showed I was sharing with both A and B and they were sharing with me, but I reshared it wasn’t working. When I reshared it, it said expired. I searched in the iPhone for “Location”, and it showed I was sharing with both of my friends, and they said the same.
Here’s the fix: But then I searched for “Find My” and it brought me to a different screen that showed Friend A wasn’t sharing with me and I wasn’t sharing with Friend B. So we all went to the “Find My” screen and shared from there, and now it works.
I don’t know why this is different than in messages or when I search “Find My” versus “Location” in the search bar. But now it’s working for all of us.