Help with Sierra Wireless MC7355
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It's probably in the wrong usb composition mode. Some modes only present MBIM or QMI interfaces which pfSense has no driver for. Since there is no way for pfSense so connect to it you would have to change the mode under Windows or maybe Linux.
I used a script to do that on the 7455 I have, linked as option 3 here:
https://github.com/danielewood/sierra-wireless-modems#create-accessible-com-portSteve
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