It's showing that unstable network,
Cannot download system update please check your connection.
In the Screen shot you attached above, nothing seems to be wrong.
Hi there, you may click on the following link to download update manually, request you to read the instructions before upgrading and take a full backup of the device before. Click here: https://www.asus.com/in/Phone/ZenFone-Max-Pro-M1-ZB601KL/HelpDesk_BIOS/
Kindly make sure you have uninterrupted internet connection.
Always try to update ur system on WIFI network as if there's slowness or network Issues in your mobile network then system will not get updated.