Quest 3 loses battery when powered off. Is that normal and can
If you are leaving a USB cable attached to it and its providing a little power, the headset will see it has a power source and not fully power off but remain in low power mode. There is also the option (at least for most people) of having the headset periodically power on to check for updates when charging (which a USB cable connected might be seen as) this option is enabled by default.