I have no trouble booting to fastboot: I simply press power + vol. up simultaneously and that’s it.
However, I always have trouble booting to custom recovery, in my case, TWRP. For my model (asus X00PD) I should press power + vol. down and then release, however, I don’t know when I have to release or if I have to press power and a bit later the vol. down button, nor do I know if the device only boots to this mode when the usb cable is not plugged in.
advice welcome
Have you tried pressing both simultaneously from off until the asus logo appears?
And then let go of power, continuing to hold volume… Maybe