Looking at the link ("How to change ZTE 4G modem from route mode to bridge mode and get a public IPv4 address on your firewall"), the third sentence states --b*cat wonders how one would achieve a disconnected state and presumes removing the SIM card would be sufficient?
Just arrived this afternoon. Am very unwell so no investigation today.
You go to 2. Change the green switch from on to off.You then go to the top right and change the mode from router to bridge.https://tunkkaamo.cloud/wp-content/uploads/2020/10/image.png