It has been now few days/a week/couple of weeks (hard to remember exactly when the problem started) that the phone, even when standing perfectly still on the desk, starts to ask the pin code for the SIM card.
I am wondering if the problem is software - has an updated was made recently - and this seems to be related to 4G, or there is some contact issue with the SIM card as the phone maybe fell one time too many.
Is there any way to make a diagnostic of the problem, to understand if it is HW or SW?
Thanks