Bug Causes Android Oreo to Eat Up Mobile Data Even When Connected to Wi-Fi
Google’s recently announced Android Oreo comes with a bug that causes mobile data to be used by devices even when a Wi-Fi connection exists, leading to huge spikes in data usage and some devices to max out their monthly data plans.
Posts on reddit seem to indicate that the one to blame is a setting in developer options which is called “mobile data always active” and which Google more or less forgot to disable when rolling out the final version of Android Oreo. The beta builds shipped with this feature enabled for testing purposes, but it was supposed to be toggled to off once the operating system was finalized.
Turning this option off is actually the manual workaround for the bug, though there were users who decided to disable mobile data completely when connecting to a Wi-Fi network.
Google already preparing a fix