There’s some instructions on ZTE forums on how to get this modem working and it *does work* but it’s convoluted.
I just created a file called /etc/modprobe.d/zte-mf633.conf
and added the following to it:
options usbserial vendor=0x19d2 product=0x0031
and then reboot with the modem in to test it works on a fresh boot. If you insert the modem *after* you have booted, you may have to unmount/eject the cdrom that it is detect as prior to it being detect in connection manager. The above may also interrupt with other usb devices, though my storage key still works and it’s all I need for now.
Then it will display as a 3G card and you can use the network wizard to configure it.
Two things to note.
1. You have to “register/signup” using a Windows computer – which I had a lot of problems with and had to end up doing it in store
2. I forget now, but it seemed noteworthy.