Sometimes when you connect these, they do not prompt to be adopted. When that occurs, change your default network to use the dream machine as it's primary DNS (192.168.1.1 then use Google's or any other 18.104.22.168, 22.214.171.124, 126.96.36.199).
As soon as you do that, reboot the LTE device, so it picks up the new DNS info, then adopt the device.
From there, adopt as normal.
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