I am trying to unlock the bootloader on my Aquarius X Pro 2. I am on Ubuntu and installed fastboot and adb and can connect via adb shell to the device or restart it into bootloader with adb restart bootloader. Also, I unlocked the bootloader in the developer options.
So when I am in the bootloader menu, I can see that the device is locked. I type fastboot devices and get this output: XZ001532 fastboot. So everything seems fine. But if I try any other command, like fastboot flashing unlock_critical or fastboot oem device-info nothing happens or I get a message like "waiting for device".
Anybody an idea what can be the problem here? I resetted the device several times, but that did not help.
Ok, after what felt years of debugging and asking for help, I was finally able to figure out the problem. I installed adb and fastboot from the outdated Ubuntu APT repos via the command line instead of downloading the current Google.zip per wiki install guide link. With the proper tools, everything works now. I hope this helps somebody else to avoid the same mistake in the future.