Speeding up 3G / LTE network connections
Speed up your 3G/LTE networks using the following tips:
Contact your network provider to check if there is problem with mobile network.
Install your SIM card on another phone to check if there is problem with your phone.
To access Safe Mode, press and hold the power key then tap Power Off > OK. If your phone is working well in Safe Mode, that means there might be third-party apps that cause malfunction when used in Normal mode. Please restart your phone and check again.
Back up your data and perform factory data reset.