GadgetsUpdated Yesterday
Weak Wi-Fi can send your phone to mobile data.
That jump from Wi-Fi to cellular data isn't necessarily a glitch. A phone may make it when the signal is weak, when a Wi-Fi network has no internet, or because an automatic-switching setting is on. The point is to keep you connected, but the switch can still interrupt a call or video—and quietly use up cellular data. If it happens only in certain rooms, weak coverage is a clue; if other devices work on the same network while one phone switches, its settings may be involved. Turning automatic switching off can leave the phone stuck on weak Wi-Fi. On iOS 27, Apple calls its feature Connectivity Assist and places it in Wi-Fi settings; older iOS versions use different instructions, and Android steps vary by model and OS.
Coverage started November 10