Hi
hayyamThank you for your asking. Kindly provide the information below so that we can better assist you.
1. Your current firmware version
Settings>System>About Phone>Software information
2. Does the issue appear right after any system/apps' download or update?
3. Please try to enter "Safe Mode". If the SMS works well in Safe Mode yet the issue remains out of Safe Mode, please check on any disturbance from the installed 3rd party apps.
# How to enter and exit "Safe Mode"
https://www.asus.com/support/FAQ/1005163/4. If the issue remains the same, please provide me the screenshot of your question and elaborate more about the situation.