Please try the below:
1. Open the auto-start settings page and cancel the auto-run for all apps that don't need to be on auto-run (some models have no auto-start option).
2. Uninstall any apps you don't use often.
3. Ensure your phone is updated to the latest version by going to Settings > System > System update.
4. Back up your data and restore your phone to factory settings.
If the issue persists, contact our Customer Support for further assistance.