@Amarurtuuq
The terminal command shouldn't have any risk, it just restarts a process. It was suggested elsewhere on the forum and I used it extensively when my phone used to stop sending/receiving MMS for reasons I could never figure out.
I wouldn't get too scared off by playing with the APN either, that can make all the difference, and doesn't take too long. Take screenshots of your current settings first, and you can always go back to that. It's easy enough to look up APN settings online for a given cellular carrier.
Some people have better luck with one APN setting for "Internet and MMS", others need to have a separate setting, one for MMS, one for Internet. It may vary by carrier or other things that I don't understand.
Even re-installing isn't a scary experience. You download the Ubuntu Touch installer, plug your phone into the computer, and then you can install without wiping data. As long as you don't unplug your phone during the process and don't wipe data, it's pretty easy.