Hi vishalsingh2918 Thank 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.
>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/