Hi 021 Thank you for your asking. We had tested the bluetooth internally with Android 9 and Android 10 V429, they all perform well. A. Because you already tried the Factory Reset, please check on SMMI test as below. Open the bluetooth first, then go to Calculator> type ".12345+=">SMMI TEST>Single Test>Bluetooth Test If any of the SMMI tests fails, kindly bring your device to the nearest ASUS repair center for device checking: https://www.asus.com/support/Service-Center-All-Countries/ If it is impossible to access the service center during Covid-19 period, please try Call us: https://www.asus.com/support/CallUs B. Do you mean that your bluetooth can not open/turn on at all? Is your device rooted or unlocked before? C. Please provide me the screenshot of your bluetooth. Can't the bluetooth detect any device? D. Please try the following steps to access recovery mode for the Factory Reset: 0. Try to back up your data with USB cable 1. Power off the phone, then keep pressing "volume down key" 2. Press "power key" and stop press " power key" once you feel the vibration. Still keep pressing "volume down key" 3. Stop press "volume down key" once you enter [Android Recovery] Screen 4. Choose "Wipe data/factory reset">"Factory data reset" 5. "Reboot system now" #Hardware Reset Guide https://www.asus.com/support/FAQ/1006346/ Please note that once the steps are completed, all data, apps, settings and personal information will be deleted.