No, you are not doing anything wrong!
Sorry, but if you did a search on this topic, you would find that most folks are not happy with using AirTags for keeping track of their pets. The important thing to keep in mind is Apple did NOT design them for tracking animals or people. They are primarily designed to help you locate a misplaced item that is typically stationary.
With that said, folks still use them as such and there is no limit to the amount of pet tag holders being sold out there.
Let me explain why using an Apple AirTag is not going to work well for this purpose:
- The AirTag relies on Bluetooth technology and the Apple Find My network to work. When a tag is outside the Bluetooth range of your iPhone (~30-40'), it will require another iPhone to pick up it Bluetooth beacon signal. If one is nearby (by chance), that phone will relay the tag's encrypted ID and that phone's GPS location to the Apple servers over an active Internet connection (either by cellular or Wi-Fi). This is where you would see location (that phone's, not the tag's) with the Find My app on your iPhone. If there is no phone nearby, then you will not see any updates, and the last known location would be displayed for up to 24 hrs.
- The AirTag will randomly "beep." This can be annoying to animals, especially ones that have been used to having a training collar. This may cause the animal to try to get rid of the tag/collar, rendering it even more useless.
If keeping track of your cat is critical to you, you should consider getting a dedicated tracker that is based on GPS, not Bluetooth technology ... as the former, will provide you will real-time location updates.
