I report a problem that I have seen many times both with RUT 240 and with RUT 200. The tests have been carried out in particular with the italian operator ILIAD with standard data plan.
In particular, I have noticed many times, regularly, that after some hours the module goes silently offline, showing in the status page that all is correct (connected, 4g signal, etc) but no data exchange with public network. It is not a DNS problem. In general the signal strenght of the area is very good.
The problem happened with several firmware revisions in past and with the latest firmware revision with RUT200.
I am sure that it is enough to enter the mobile wan settings, and save the settings by keeping the same settings (apn, etc) and the connection restarts after few seconds.
Thank you very much