Hi
kglcThank you for your asking. First of all, please tell me that do you intent to update to the latest version (WW-15.2016.1907.519)? Kindly provide the information below so that we could better assist you.
1. The screenshot of your firmware version
Settings>System>About Phone>Software information>Build Number
2. The screenshot of your storage
Settings>Storage & memory
Please make sure that your storage could not be completely full.
3. The screenshot of your system update setting
Settings>System>System updates>tap 3 points at the top row>Auto-downloaded system update
For updating, please turn on auto update for same Android version update, and manual update for different Android version update. Please make sure to back up your data before updating.
#Manual Update Guide
https://www.asus.com/support/FAQ/1009748/#ZC554KL Firmware Spot
https://www.asus.com/Phone/ZenFone-4-Max-ZC554KL/HelpDesk_BIOS/