This is currently a known bug within both the Android and iOS XYO Network App. However, there is nothing broken or wrong with the hardware of your device. This means you won't need an exchange!
Because it is a bug within the software of the app, and so you will need to wait for a new app update to fix this bug.
An import sentinel feature will be available in the near future using the XYO Network app of your choice, either for Android or iOS. This will allow you to add the sentinel to your account even though a setting is out of place causing it to come up as "already claimed." This can happen occasionally but doesn't indicate the sentinel was possessed by anyone. We're sorry for the inconvenience.
In the meantime, it won't affect your functionality except that you won't be able to make changes to the sentinel or see it in your account, meaning that the only things you can't do are give it or name or set its password.
The sentinel can still bound witness when you're using the XYO Network app, and you can still use it to geomine with COIN.
The "claimed" SentinelX can still be near a device to earn 12X rewards, and can still be paired to the COIN App with a BridgeX for Sentinel Sharing.
We should have an update soon on the fix, in the meantime, please check out our help center.
Here is an updated Sentinel Guide with COIN
And here are other resources you may find useful: