How to Fix Xiaomi Phone Stuck on 'Optimizing App' Screen

Xiaomi mobile data not working is usually caused by a network setting problem, incorrect APN values, SIM restrictions, or a temporary HyperOS data connection issue. The fastest fixes are restarting the phone, checking mobile data and preferred network mode, resetting APN settings, and updating carrier or system settings.

Steps

Restart the phone and re-enable mobile data

Turn mobile data off, wait a few seconds, then turn mobile data back on. Restart the Xiaomi phone to clear a temporary network registration error.
Check SIM status and signal

Confirm that the SIM card is detected and shows signal bars. Test calls or SMS. If calls also fail, reinsert the SIM card or test the SIM in another phone.
Review APN settings

Open the mobile network settings and verify the Access Point Name provided by the carrier. If APN values look wrong or empty, use Reset APN or manually enter the correct settings. This is the most common fix APN Xiaomi step.
Set the correct preferred network type

Choose 4G/5G auto mode if the plan and area support it. In weak coverage areas, switching temporarily to LTE only can help stabilize data.
Reset network settings and check updates

Reset Wi-Fi, mobile network, and Bluetooth settings if the problem started after a system change. Install available carrier profile or HyperOS updates if a HyperOS data connection issue appeared after an update.

Common Issues and Fixes

Mobile data icon shows, but no internet: likely cause is wrong APN or DNS conflict; fix by resetting APN and toggling airplane mode for 30 seconds.
Data stopped working after a HyperOS update: likely cause is a software-side network configuration glitch; fix by resetting network settings and installing the latest patch.
Only one SIM has no data: likely cause is the wrong default data SIM; fix by selecting the correct SIM for mobile data in SIM settings.
5G or 4G connects briefly, then drops: likely cause is weak carrier coverage or unstable auto-switching; fix by forcing LTE/4G mode and testing again.
Data works after reboot, then fails again: likely cause is a carrier restriction, expired plan, or background data saver rule; fix by checking account status and disabling data saver for affected apps.

Quick Tips

VPN, private DNS, or firewall apps: these can block mobile data even when signal looks normal.
Roaming data: this must be enabled when using a secondary region SIM or traveling near a border.
Manual APN save: some carriers require a manual APN save before data starts working after SIM insertion.
App-specific failure: if only specific apps fail, the issue may be app-level background data restriction, not a full Xiaomi mobile data not working error.

💡Protip:

If mobile data connects for a moment and then stops, test by disabling VPN, private DNS, firewall apps, and data saver before changing deeper network settings.

Why is Xiaomi mobile data not working but Wi-Fi works?

Wi-Fi working normally usually points to a carrier, SIM, or APN problem. Resetting APN and confirming the active data SIM often solves the issue.

How to fix APN Xiaomi settings quickly?

Use the carrier’s official APN values or tap Reset APN in mobile network settings. Incorrect APN name, APN type, or authentication fields can prevent data access.

🤔Note:

If mobile data stopped working after backup, reset, or ROM changes, a local backup of contacts, photos, and network-sensitive files can help before deeper troubleshooting. For device management and backup, Dr.Fone can be a practical option at the final troubleshooting stage.

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