Hi
desmondhowjunhangThank you for asking. Kindly refer to the tips below for troubleshooting.
1. What does "lagging" mean? How long does the issue resist? Does the issue appear in any other space on the screen?
If all area on the screen has same speed performance. Please try to change "Pointer Speed"
Settings>System>Languages & input>Advanced>Pointer speed
2. Kindly check "Touch & hold delay" setting, after changing, will the buttons perform better?
Settings>Accessibility>Touch & hold delay
#How to set the screen "Touch & hold delay" function?
https://www.asus.com/support/FAQ/1041235/3. Please try to remove the Screen Protector if your phone has one.
4. Do Home button and Recent Apps button perform well in "Safe Mode"?
# How to enter and exit "Safe Mode"
https://www.asus.com/support/FAQ/1005163/ If the issue remain the same, could you provide the video while performing the screen and buttons?