The short answer
Turn off the setting that switches to mobile data when Wi-Fi is weak, because it is the most common cause of a phone that appears to drop Wi-Fi. Then forget and rejoin the network, turn off Wi-Fi scanning throttling, and check whether battery saver is suspending the connection.
A phone disconnecting while the television and the laptop stay connected is doing something the other devices do not: deciding, continuously, whether Wi-Fi is worth using. That decision-making is where most of these problems live.
Cause 1: automatic network switching
Both Android and iOS include features that switch to mobile data when Wi-Fi seems poor. When the phone is at the edge of coverage, it switches back and forth, which the user experiences as Wi-Fi dropping.
On Android, turn off adaptive or smart network switching
Settings, Network and internet, Wi-Fi, Network preferences. Names vary by manufacturer: Switch to mobile data, Adaptive Wi-Fi, Smart network switch.
On iPhone, turn off Wi-Fi Assist
Settings, Mobile Data, at the bottom of the list.
Turn off auto-connect to open networks
Which causes the phone to jump to a neighbour’s open network or a captive portal.
Remove old saved networks
Particularly ones with the same name as yours, such as an old extender still saved.
Cause 2: battery optimisation
Battery saver modes reduce Wi-Fi activity and can disconnect entirely when the screen is off. The tell is a phone that has no notifications until you unlock it, and Wi-Fi showing as connected the moment you look.
Turn off battery saver and test. On Android, also check the manufacturer’s own battery manager, which is separate from the Android setting and usually more aggressive.
Cause 3: the network itself
- A full DHCP pool, which prevents the phone getting an address when it tries to rejoin. Enlarging the pool and shortening the lease resolves it.
- Band steering, pushing the phone between 2.4 and 5GHz. Splitting the bands into separate names is a definitive test.
- Two access points with the same name but different passwords or security settings, which causes repeated failed associations.
- An extender with a weak link, which the phone connects to and then loses.
- Router firmware, which occasionally causes client-specific problems and is worth updating.
- WPA3-only security, which older phones handle badly, sometimes intermittently rather than failing outright.
Randomised MAC addresses are worth checking. Phones use a different MAC address per network for privacy, and a router with MAC filtering, a device-specific rule or a fixed address reservation will stop recognising the phone after the address rotates, typically following a system update. Setting the phone to use its device MAC for your home network only resolves it.
Cause 4: the phone’s own state
- Forget and rejoin the network, which clears a stale profile with outdated security parameters.
- Reset network settings, which clears all saved networks, Bluetooth pairings and mobile settings. It resolves stubborn cases and requires you to rejoin everything.
- Restart the phone, which clears a hung Wi-Fi service.
- Update the system, since Wi-Fi handling improves with updates and regressions do occur.
- Test in safe mode on Android, to rule out a VPN or network-related app interfering.
- Check for a VPN or private DNS that is failing and causing the phone to consider the network unusable.
Cause 5: signal and position
Phones are held in hands, which absorb 2.4GHz effectively, and carried into rooms at the edge of coverage. A phone that drops in one specific room is telling you about coverage rather than about itself.
Check the signal in that room with a Wi-Fi analyser, and compare against where the phone works reliably. If the problem tracks your position, the answer is coverage: move the router, add a mesh node, or accept that the far bedroom is marginal.
Cause 6: the case and the hardware
A case with a metal plate for a magnetic mount attenuates the signal. So does a heavily armoured case. Testing without the case takes seconds.
Genuine Wi-Fi hardware failure is rare in phones and does happen after water exposure or a drop. The signature is consistently worse signal than other phones in the same place, in every room, after a network settings reset.
If the phone drops Wi-Fi and mobile data simultaneously and repeatedly, that is not a Wi-Fi problem. Look at the phone’s general stability: overheating, a failing battery unable to supply peak current, or a system fault. A phone that loses all connectivity at once is describing something more fundamental.
Why does my phone switch to mobile data at home?
A feature designed to keep you connected when Wi-Fi is weak. At the edge of coverage it switches repeatedly, which feels like Wi-Fi dropping. Turn off Wi-Fi Assist or adaptive network switching.
Why does Wi-Fi disconnect when the screen is off?
Battery optimisation suspending the connection. Turn off battery saver and check the manufacturer’s own battery manager, which is separate and usually more aggressive.
Why did this start after a software update?
Updates rotate the randomised MAC address and can change security negotiation. Forget and rejoin the network, and check any MAC-based rules on your router.
Should I reset network settings?
It resolves stubborn cases and clears every saved network, Bluetooth pairing and mobile setting. Try forgetting the single network first, since that is far less disruptive.
Why does only my phone have this problem?
Because only the phone is continuously deciding between Wi-Fi and mobile data, moving around the house, and being held in a hand that absorbs signal. Fixed devices do none of those things.
The order
Turn off Wi-Fi Assist or adaptive network switching, which explains most cases. Turn off battery saver, including the manufacturer’s own. Forget and rejoin the network, and remove old saved networks with similar names. Check the router’s DHCP pool and consider splitting the bands. Test without the case, and if the drops track a specific room, treat it as a coverage problem rather than a phone problem.
