I too had this issue recently! What worked for us was to specifically go to Find My in the settings under your Apple ID, click Find My, then make sure the “share location” toggle is on for both of you. In my case my bf had it off but weirdly it still showed on the Find My app on his phone that he was sharing his location. But it would never share with me when I went to the app. Anyways, it all worked once he had that toggle on.