Hi
vishalsingh2918Thank you for your asking. Kindly provide the information below so that we could better assist you.
>VoLTE
1. Model Name: Settings>System>About phone
Refer to the link below to check the model name by model no. in the link
https://www.asus.com/support/FAQ/1014441/ #Please notice that VoLTE is only available in some models.
2. Your current firmware version
Setting >System>About Phone>Software information
If you try to update to the latest version, does the issue still remain?
3. Can this SIM card's 4G/VoLTE service operate in other phone? What's your 4G service operator name.
For further information about VoLTE, please check the link below.
https://www.asus.com/support/FAQ/1030125/>Can't Open Settings Icon
1. Does the issue appear in any other space on the screen? Please try to remove the Screen Protector if your phone has one.
2. Does there have any relative issue? Does screen perform well in "Safe Mode"?
# How to enter and exit "Safe Mode"
https://www.asus.com/support/FAQ/1005163/