Audio HAL (Hardware Abstraction Layer) mismatch. Fix: In Settings → Sound → "Force HDMI audio." If that fails, install the ALSA Mixer app and manually unmute rk-hdmi .
sudo upgrade_tool di -b boot.img sudo upgrade_tool di -u super.img sudo upgrade_tool di -m misc.img sudo upgrade_tool di -r recovery.img Rk3328 Firmware Android 11
Upgrading an RK3328 device to Android 11 isn't always seamless: Wi-Fi/Bluetooth Drivers Audio HAL (Hardware Abstraction Layer) mismatch
An RK3328 Android 11 firmware package typically includes: Rk3328 Firmware Android 11