Why does my Xiaomi Mi 9 SE's Wi-Fi keep disconnecting and have a weak signal?

There can be several reasons why your Xiaomi Mi 9 SE's Wi-Fi may be disconnecting frequently or exhibiting a weak signal. Here are some potential causes and troubleshooting steps you can try:

Xiaomi Mi 9 SE

1. Distance from the router: Make sure you are within a reasonable range of your Wi-Fi router. If you are too far away, the signal strength can weaken, leading to intermittent disconnections. Move closer to the router and see if the issue persists.
2. Signal interference: Other electronic devices or appliances near your phone or Wi-Fi router can cause interference with the Wi-Fi signal. Keep your phone away from devices like cordless phones, microwave ovens, or Bluetooth devices, as they can disrupt the signal. Additionally, neighboring Wi-Fi networks operating on the same channel can interfere. Try changing the Wi-Fi channel on your router to reduce interference.
3. Router settings: Check the settings on your Wi-Fi router. Ensure that the router firmware is up to date and that it is configured to provide a stable Wi-Fi signal. You can consult your router's user manual or contact your Internet service provider (ISP) for assistance with router settings.
4. Network congestion: If multiple devices are connected to your Wi-Fi network simultaneously, it can lead to congestion and reduced signal strength. Disconnect devices that are not actively being used or consider upgrading to a router that supports higher network capacity.
5. Wi-Fi sleep policy: Some smartphones have a feature called Wi-Fi sleep policy that conserves battery power by automatically turning off Wi-Fi when the device is idle. Check your phone's settings to ensure this feature is disabled or adjust the settings to keep Wi-Fi active even when the phone is idle.
6. Clear network settings cache: Clearing the network settings cache on your Xiaomi Mi 9 SE can sometimes resolve connectivity issues. Go to Settings > System apps > Wi-Fi > Storage > Clear cache and clear the cache.
7. Forget and reconnect to Wi-Fi network: Forget the Wi-Fi network on your phone and then reconnect to it. Go to Settings > Wi-Fi, tap on the network name, and select "Forget." Afterward, reconnect to the Wi-Fi network by selecting it from the available networks list.
8. Factory reset: If none of the above steps work, you may consider performing a factory reset on your Xiaomi Mi 9 SE. Keep in mind that a factory reset will erase all data on your device, so ensure you have a backup before proceeding. To perform a factory reset, go to Settings > About phone > System update > Three-dot menu > Reset to factory settings.

If the issue persists even after trying these troubleshooting steps, it is advisable to contact Xiaomi customer support or take your device to an authorized service center for further assistance.