Apple has just released watchOS 4.0.1 to the public. Only for Apple Watch Series 3 models, it can be downloaded now through the companion Watch app on your iPhone by heading to General > Software Update in the My Watch portion of the app.
Your watch needs to have more than 50 percent power and connected to a charger.
The software update fixes an issue discovered with Series 3 models with LTE.
Using watchOS 4.0, the Apple Watch would incorrectly attempt to login to a captive Wi-Fi network, like at Starbucks, that features an interstitial page. When doing that, the watch wouldn’t switch to an LTE connection.
Any user would need to toggle Airplane Mode on the Apple Watch for it to connect to LTE.