[Phone] Phone system crashed or system is unstable

Please follow steps below for troubleshooting:

1. Memory clearner: Slide down the screen from upper area to access Quick settings and then tap Memory Clearner. 

2. Uninstall apps that are not often used: Settings > Apps > (select an app) Uninstall. 
　＊If you don't see the Uninstall button, or if you only see the option to Uninstall updates then the selected app cannot be permanently removed from your device. The app is likely a system app that can't be uninstalled. 

3. Clear cache of apps：Settings > Apps &notifications > App info > select apps that may cause malfunction > Clear cache. 

4. Launch Play Store and update all apps. 

5. Reboot your phone. 

6. Update firmware to latest version：Settings > System> System updates > Check now. 

7. Access Safe Mode by long pressing power key > tapping and holding Power Off > tapping OK. If your phone works well in Safe Mode, there may be some 3rd apps that cause malfunction. Please reboot your phone and check again if it works well. 

8. Backup your data and perform factory data reset.