Asus has already confirmed that the ZenFone 5 Lite will upgrade to Android 9.0 Pie with ZenUI 5 in the first quarter of 2019, so you don’t need to wait too long to get new features of Pie and UI changes on the phone. Apart from the aforementioned functions, the 14.0400.1811.061 update also includes updated APN list and latest Google security patch.

Official changelog: As usual, the OTA update is rolling out in phases, so it will take few hours or even few days/or weeks to reach on all devices. If you have not received the OTA notification for the update yet, check it manually by going to Settings > System > System updates to check for the update. Experienced users can install the update manually. ASUS has made available full firmware for download, if you cannot install the OTA or if you are out of Wi-Fi coverage area.

Downloads:

You can download ZenFone 5 Lite ZC600KL_ WW_14.0400.1811.061 full firmware from Asus website here.

Installation:

  1. Double click the downloaded firmware zip file to see another zip file it. If another in it, unzip the downloaded file.
  2. Connect your phone to your PC, move the update zip file to the root directory of your phone’s internal storage and then disconnect from PC.
  3. You will see firmware update notification popped up on status bar
  4. Select it and follow steps to update firmware. After completing the installation, your ZenFone 5 Lite will reboot into the new version. (Source)