Apple chief executive Tim Cook unveiled the latest Apple Watch last week in California. (Josh Edelson/AFP/Getty Images)

The main selling point of Apple's new version of its Watch is that the device can connect independently to cellular networks, making calls and running navigation on its own without being tethered to the iPhone. But on Wednesday Apple acknowledged that this centerpiece feature isn't working as intended.

Apple addressed the issue after two reviews of the Watch from the Wall Street Journal and the Verge cited problems with connectivity. The Watch is supposed to switch seamlessly between WiFi and cellular networks. In a statement, Apple said that the problems arise when the Watch tries to connect to certain WiFi networks. "We have discovered that when Apple Watch Series 3 joins unauthenticated WiFi networks without connectivity, it may at times prevent the watch from using cellular. We are investigating a fix for a future software release.”

“Unauthenticated WiFi networks without connectivity” refers to a very particular — but not uncommon — type of connection. Networks in places such as Starbucks or in airports, for example, often automatically connect to devices, particularly if the device has connected to the network before. But they also often ask users to take an extra step, such as accepting terms and conditions, before they actually connect. Those dialogues don't appear on the Apple Watch, which then gets stuck thinking it has joined a familiar network when it hasn't.

It's rare for Apple to ship even its early reviewers a product with a notable problem. There was a similar snag with the September 2012 launch of Apple Maps, which placed some landmarks in odd places and made others appear as if they were melting. Apple chief executive Tim Cook apologized for the rocky Maps launch — a stark contrast to that attitude held by his predecessor, Steve Jobs, who once told people who were having trouble with their iPhone's connectivity to hold their phones a different way.

A problem connecting to cellular networks would be a blow to an important Apple product and undercut the main reason for buying the $399 version of the Watch that connects to LTE and carries its own data plan costs. Yet Apple's explanation indicates that connecting to cellular networks isn't the problem — just the device's confusion about when it should stay off WiFi.

It's not clear when the fix be released. The new Watch is still set to go on sale Friday.

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