@mikeand if you are still interested in solving this issue, you could try the following:
with Ubuntu Touch started, open a terminal and make the root partition writable writeable:
sudo mount -o rw,remount /
Edit the ril_subscription.conf (There are two files, the FP3.conf should be leading, but to be sure, edit both):
sudo nano /etc/ofono/ril_subscription.conf
# and
sudo nano /etc/ofono/ril_subscription.d/FP3.conf
Add useDataProfiles=true:
# Ofono configuration for FP3
[Settings]
#EmptyConfig=false
#Identity=radio:radio
#3GLTEHandover=true
#SetRadioCapability=auto
SetRadioCapability=off
emptyPinQuery=false
radioPowerCycle=false
confirmRadioPowerOn=false
useDataProfiles=true
[ril_0]
transport=binder:name=slot1
name=slot1
[ril_1]
transport=binder:name=slot2
name=slot2
Then save it, selecting the "Nano" keys at the burger-menu above the keyboard and tapping "Ctrl-X", then hitting "y".
If everything is done, reboot the device.