watchOS 4.0.1 can be downloaded through the dedicated Apple Watch app on the iPhone by going to General –> Software Update. To install the update, the Apple Watch must have 50 percent battery, it must be placed on the charger, and it must be in range of the iPhone. Today’s update is only for the Apple Watch Series 3 models.
watchOS 4.0.1 addresses a serious Wi-Fi bug impacting the performance of the new LTE-enabled Apple Watch Series 3 models.
watchOS 4.0.1 fixes issues that in rare cases were causing Apple Watch to join unauthenticated (captive) Wi-Fi networks, such as those found in public places like coffee shops and hotels, which direct the user to a web page before the network can be accessed.
During the review period for the new Apple Watch, testers discovered that the device would frequently disconnect from LTE, choosing to connect to an unusable Wi-Fi hotspot instead of an LTE tower due to its preference for Wi-Fi to save battery.
The Apple Watch was mistakenly connecting to free Wi-Fi hotspots that have interstitial agreement pages to use the service. With no way to see the page or confirm, LTE Apple Watches couldn’t actually use the Wi-Fi, but it still prevented them from connecting to LTE.
Apple said it was aware of the issue just before the Series 3 models launched, and said it was investigating a fix for a future software update, which is available today.