For now, I’ve found out that turning off LTE/4G is the only way I can maintain my signal and data, that means: only 3G.
After changing this, more than one week without loosing the connection.
Once I tried to return the 4G, in less than 10 minutes, the signal and a data were lost again. So, I’ll keep using only 3G to avoid getting more frustrated.
Haven’t tried, yet, to get a new SIM Card on Windtree (Italy) but thinking that this should be a nice try.
Frustrating... 😕