If iPhone Disconnects from Wi-Fi whenever it is locked or goes in sleep mode, you will have a hard time making calls and browsing on the internet using Wi-Fi Network.
The problem of iPhone disconnecting from Wi-Fi when locked could occurring due to Wi-Fi Assist feature being enabled on your device to corrupted network settings and other reasons.
iPhone Disconnects from Wi-Fi When Locked
In general, the most common reason for While users have reported about this problem being fixed after installing updates, you can try other troubleshooting steps as provided below, if the problem persists after the update.
1. Turn OFF Wi-Fi Assist
The problem could be due to the Wi-Fi Assist feature on your device switching iPhone from Wi-Fi to Cellular Network.
1. Go to Settings > Cellular.
2. On the next screen, move the toggle next to Wi-Fi Assist to OFF position.
After disabling Wi-Fi assist, reconnect your device to Wi-Fi network and see if Wi-Fi is now working properly on your iPhone.
2. Set iPhone to Automatically Join Known Networks
The chances of iPhone disconnecting from Wi-Fi are greater if your device is not set to automatically join known Wi-Fi networks.
1. Go to Settings > Wi-Fi > scroll down and tap on Ask to Join Networks.
2. On the next screen, select the Ask option.
This will allow iPhone to automatically join known Wi-Fi networks.
3. Disable Wi-Fi Networking Service
Some users have reported fixing this issue by disabling Wi-Fi Networking service.
1. Go to Settings > Privacy & Security > Location Services.
2. On the next screen, scroll down to bottom and tap on System Services.
3. On the next screen, move the toggle next to Networking & Wireless entry to OFF position.
4. Forget Wi-Fi Network and Rejoin
Forgetting Wi-Fi network and re-joining the network is known to help in fixing Wi-Fi connectivity issues.
1. Go to Settings > Wi-Fi > select your Wi-Fi network.
2. On the next screen, select Forget This Network option.
3. On the confirmation pop-up, tap on the Forget option to confirm.
4. Wait for 60 seconds > select your Wi-Fi Network > join Wi-Fi Network by entering your Wi-Fi password.
5. Reset Network Settings
If above methods did not help, you can go for a Network Settings Reset and see if this helps in fixing the problem.
1. Go to Settings > General > Transfer or Reset iPhone > Reset.
2. On the pop-up, select Reset Network Settings option.
3. Enter your Lock Screen Password (if prompted) > On the confirmation pop-up, select the Reset option to confirm.
4. Patiently Wait for the Reset process to be completed.
After the Reset process is completed, you will be asked to rejoin Wi-Fi network by entering your Wi-Fi network password.