Back in the dawn of 3G days, many cell phone did have this problem because 3G towers are sparse. Nowadays, you mostly locked on to LTE, sometimes 3G/4G. Most phones rarely ever see 2G. Given Watch's smaller size and no LTE support, it could fall back to 2G signal when it can't lock on to a 3G (or so-called 4G by AT&T) signal. When this happens, you typically see your phone gets a wrong time zone.
In your case above, you simply need to wait a few minutes for network time to sync in. Why it didn't happen with phones? How many Tizen phone have you used before ? My guess is zero. If it is so easy to create your own phone OS, everybody will do it. Samsung, driven by greed, choose to have its own phone OS called Tizen in order to get away from Google.