I have a 2017 MBP 13" no touchbar, when I connect an external drive (USB stick to dongle to Mac or SATA SSD to adapter to Mac), it will allow me to copy the data between the internal storage and external, but I can't prevent it from copying. i've tried holding down Command, Option and Control one at a time and they don't help.
I also have a 2011 MBP 13" on 10.12.5 which works property (press commend to move). I don't know if this is a bug in 12.6 or there is something wrong with the new Mac.
I also have a 2011 MBP 13" on 10.12.5 which works property (press commend to move). I don't know if this is a bug in 12.6 or there is something wrong with the new Mac.