Hi
Natalie R.Thank you for your asking. Kindly provide the information below so that we could better assist you.
1. Your current firmware version
Settings>System>About Phone>Software information
If you try to update to the latest version, does the issue still remain?
2. Does the issue appear after any system/apps' download or update?
3. Does the issue happen in build-in texting app or other apps, too? Which apps?
4. Please try to enter "Safe Mode". If the function 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/