"Find My" issue with iOS 15.3.1 update on iPhone?

I can no longer track my children through the Find My app after the iOS 15.3.1 update. My kids refreshed their location sharing to my phone, but nothing is coming up. This is an essential safety feature that I need for my kids. Can someone walk me through how to get their information back on Find My people? I don't want to activate family sharing. Thanks for your help!