Mine has been experiencing this since the update also. Very frustrating. The only thing different for my series 3 LTE watch was that I had changed my weather app from Carrot to a couple others to try out. The new ones were Forecast Bar and MyRadar. They worked fine before the update. After the update, I kept experiencing missing data and then the reboots. Finally decided to reload Carrot to see if that made any difference (keeping the other two apps still on my phone/watch) but not using in any complications. I have experienced no issues in the last 24 hours. Hopefully it stays that way.