How to boot sparkylinux from a usb3 port?

[djh]

Last night I created a sparkylinux gameover installation on a usb3 stick with three partitions (root = ~20GB, /home = ~9GB, swap = 2GB).

The problem is that it refuses to boot if I insert it in one of my laptop's usb3 ports, it only works from a usb2 port.  Any ideas how to fix that?

By the way, my laptop is a Lenovo Thinkpad T430 which is generally an extremely good fit for Linux distros and this is the first time I have had trouble booting off one its USB3 ports.