Thanks for this, I have a MiFi device that was working fine, then it suddently stopped with this exact same issue. 4G connected, I couldn’t ping anything, but curiously nslookup worked using 127.0.0.1 or using one of the dns servers shown in the output from:

uqmi -d /dev/cdc-wdm0 --get-current-settings

so clearly something was getting through. No other DNS servers worked, however.

Anyway, the fix was simply to open the web interface, manual config of the 4G device, change the device from /dev/cdc-wm0 to /dev/ttyUSB2, and then it immediately worked. After that I changed back to /dev/cdc-wm0, and it’s still working.

Thanks for sharing!