Comment 1 for bug 1451249

@David

Thanks for the bug report. From your bug description, I don't think you're hitting bug #1435328 as your network indicator shows no connection, whereas the scenario in that bug was that the indicator showed a valid mobile data connection when the connection actually had disconnected. That bug's been marked FixReleased and the related fix to ofono should be released as an official update imminently.

Regarding your specific problem, I'm assuming you've set 'Data Roaming' to enabled per bug #1449990?

Are you familiar with adb and/or shh, could you reproduce the described scenario again and attach the file /var/log/syslog from the phone?

Finally, you say: "when the phone silently switches from O2-DE to o2-de+ or vice versa, the mobile data connection disappears, the symbol that appear is just the empty "angular" signal, if the screen is locked, and nothing works".

Do you mean that you screen is on, but locked and you see the data indicator disconnect? Or did the screen go off, and when you wake the phone the network indicator shows disconnected before you've unlocked it?

Have you tried toggling flight-mode and/or mobile data to see if either also triggers a re-connect?

Finally, if you're using more than one SIM, can you please ensure that the SIM selected for mobile data is correct in Cellular Settings? We had an earlier bug on the BQ phone where this setting could change from one SIM to the other. This was fixed in one of the early updates, however it's still worth double-checking.