The watch is supposed to sync time with the phone but it does not. The option to fix the time on the watch is grayed out, because it is supposed to sync. This, and many other issues, happened immediately after the last phone and watch update. Galaxy S8+ with Gear S3 (D348).
Same problem here. S3 Frontier does not sync time whith my phone (S7).
The watch is assuming the daylight saving time, that in my area (São Paulo - Brazil) is going to start only on 04 Nov.
Software version R760XXU2CRH1
Security Status TZPF_SM-R760_3.0_0001
My Time Zone: BRT UTC-3H
Time and date on my S7: automatically. Phone shows the correct time.
Actually, the watch does not simply update with the time through connection with the phone. I am traveling overseas and they do not recognize DST in this country and my watch and phone are an hour apart even though they are linked by Bluetooth. My phone has the local time and my watch reflects an hour behind, DST.