Please tell us some basic information before asking for help:
Model Name: ZenFone 9 16/256GB
Firmware Version: VW_32.2030.2030.26
Rooted or not: No
Frequency of Occurrence: unpredictably
APP Name & APP Version (If your issue relates to the app):
In addition to information above, please also provide as much details as you can, e.g., using scenario, what troubleshooting you've already done, screenshot, etc.
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Double tap on the back only sometimes works even without the back cover of the phone. When I need this function to work, most of the time the phone does not respond at all even after tapping hard on different parts of the phone.