Create an SD image from working BeagleBone

I have an ‘updated’ BeagleBone with Mender that I want to clone. When I use beaglebone-black-make-microSD-flasher-from-eMMC to make an SD card, and burn that on another BBB, the Mender functionality goes away (I can’t access Mender from my ‘new’ BBB).
Am I going about this right? Whay do I need to do to make an image I can move to another BBB?

George R