Just a follow up on this as I got two MX67C recently so I am testing this out.
First time powering this MX67C on
I already installed the AT&T NANO-SIM card
WAN 1 connection active
After a few minutes, it downloaded firmware and rebooted. The Cellular interface did not show anything until after the reboot. Then I saw it (live) populate information.
Screenshots below
Status only says 'READY'
When I click on the edit icon, it has 'disabled' already highlighted. Not sure if that means anything.
I manually selected Enabled and now the status shows 'READY, ENABLED'
So I'm pretty sure that we don't need to do anything (like clicking enabled). I'm going to test this on the second one and see if when I unplug WAN 1, the cellular kicks in automatically (without me doing anything GUI wise).