If your AirTag is not showing up in the Find My app on your iPhone, here are some troubleshooting tips to make it appear again.
Apple AirTag Not Working? 10 Tips to Fix AirTag Issues
AirTag Not Connecting: Quick Troubleshooting Guide - GadgetMates
How to find, block, and disable an AirTag that's tracking you
Fixed: AirTag Not Showing Up in Find My App!
Apple AirTag Not Working? 10 Tips to Fix AirTag Issues
Your connection is not private - Apple Community
Send me your seatpost shapes to build an Apple AirTag Mount - Equipment - TrainerRoad
How to avoid unwanted tracking if an unknown AirTag is moving with you
How To Fix 'Could Not Complete AirTag Setup' Error Message- The Mac Observer