“Waiting for device” might be different from the conclusion that the device is locked, idk … but you might use Windows device manager to ensure you have fully dealt with the drivers issue.
In this thread (for a different device) I described a way to check with Windows update. Installation- received a “< waiting for any device” message - #2 by aibd
In the documentation https://doc.e.foundation/devices/axolotl/install we see that fastboot devices has to succeed before Unlocking the bootloader.
Here is another “Waiting for any device” post *waiting for any device* issue when installing FP4 -> SOLVED