Is your USB got enough memory for extra storage and writing? Needs to be able to write as well as read.
As for the second, did you duplicate the USB identically for your second? I only ask because every separate rig needs a fresh install/OS as every device has unique serials etc so would be buggy to duplicate a USB OS.
My first pendrive was 16gb usb3.1 brand new
My second pendrive is 32gb. I flashed it from the iso on my computer.