After restarting and repeating the prodedure. The only solution for this, for me, has been restarting the PC, since can't use another USB port at this particular PC for now. 'adb devices' on stock recovery sideload activity or 'fastboot devices' on the bootloader don't return any device, and if I reboot onto Android and I connect the usb cable, android recognizes it as only a charging cable and doesn't even show the options to connect to pc (charge only, mtp, camera, etc.). When doing adb reboot booloader / adb reboot recovery, the phone enters the selected mode, but it seems that the connection to the device is completely dead. Having an issue lately on 6.0~6.0.1 that I didn't ever have before.
