Hi there, request you to update your device to the latest software version. 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/Regarding the charging issue, , in order to help you kindly help us with the following details:
1. Kindly let us know the Charging time taken from 0 - 100%.
2. What's the charging time difference between the current & previous update.
3. Try another charger & let us know if there is any difference.
4. Use the ASUS charger on a different phone & let us know the difference.