Did you ever find a solution? I am also unable to reset one of my tags. I was able to successfully reset other tags. Tested the batteries, and tried batteries from other working tags.
Hello, welcome to the Samsung Community. I understand your concerns on resetting your Smart Tag and I will be more than happy to take a look into this with you.
I know that you stated that you have tried to reset the tag by removing the battery and pressing the button but have you tried deleting the tracker from the SmartThings app?
If the SmartThings Tracker is reinitialized, it will be reset. To do so, you must delete the tracker from the SmartThings app. When it's deleted, it will initialize itself so it can reconnect to SmartThings. At which time, you'll be able to connect and register the tracker.
Before you delete the tracker from the SmartThings app, ensure it's not in motion. When the tracker is deleted, any associated Automations or Scenes will also be deleted.
From your phone, navigate to and touch the SmartThings app
Touch the Menuicon from the left side, and then select the tracker's location from the touch the Location Drop Down menu
Touch the Menu icon again, and then touch Devices
Touch More Options (3 vertical dots) icon in the upper right corner, and then touch Edit
Touch the Remove icon (minus sign) next to the tracker, and then touch DELETE to confirm the removal
Once the tracker is deleted, it will be initialized. The LED will flash blue during this time
When the LED blinks red, green and blue, the tracker is ready to connect with SmartThings. If the LED isn't blink red, green and blue, restart the tracker
If you're not ready to connect the tracker with SmartThings again, press and hold the Power button for three seconds to power it off. The LED will blink three times before powering off.
