Jetson Mate TTY not found

The Jetson Mate Getting Started wiki says to identify the connected serial port by typing dmesg | grep tty at Step 15. Whether I restart the Mate in normal mode or recovery mode, I don’t find any listing for ACM. usb-devices | grep -C4 -i APX does find the device in recovery mode, and I was able to install the Jetson OS, but not the SDK Components.

What am I doing wrong?