Using my Galaxy Watch LTE with my Galaxy S8 Active. I already set up a wearable line of service with AT&T, but when I try to connect my watch to the mobile network it says (in the Galaxy Wearable app) my watch isn't compatible with AT&T's network yet and to check for updates for future compatibility. I have updated my watch through the app and still no ability to connect to my standalone LTE service.
Also, my watch shows it still has the original Tizen 126.96.36.199 firmware. I can't figure out if this is the issue, and if so, how to manually update the Tizen firmware. Attempting to update through the Galaxy Wearable app seems to never affect the firmware version on my watch. It tells me my watch is up to date.
Can I ask where the watch was purchased? Was it ever connected to any other carrier lines?