BEAGL-BONE-BLACK: Openthread Border Router configuration

Dear Suport,

I came across a very strange phenomenon when we tried to build Openthread Boarder Router on BBB.  First, I followed the steps described in the following link to set up my BBB. 

https://openthread.io/guides/border-router/beaglebone-black

Then I followed the description in the following page.

https://openthread.io/guides/border-router/build

I use an external USB WLAN dongle and which we can connect the internet without problem.  However, when I ran to the following steps, my SSH on USB disappears and I could not to access my BBB anymore. 

INFRA_IF_NAME=wlan0 ./script/setup

I wonder why this script would destroy the USB Network card for SSH.  Is there any thing I missed?

Vincent