Hi
zammwee03Thank 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>Build Number
If you try to update to the latest version, does the issue still remain?
**My ZC554KL return and recent buttons work well in WW-15.2016.1907.519
2. 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"
[Phone/Pad] How to Enter and Exit Safe Mode? | Official Support | ASUS Global3. Does the issue appear after any system/apps download or upgrade?