Signal drops when 24hr passport renews

[Zoe411]

Im in Italy with my husband & we both have iPhones. I have had no issues auto connecting to the network, but my husband's phone looses connectivity every 24hrs, in line with the passport text/ renewal. 
no spend caps set & switching on/off doesn't work.  

battery was around 30% when this happened today.  
on both occasions we had to toggle auto connect Off (in settings) and manually select the network that my phone has auto connected too. Then it wakes up. 

his network set up is identical to mine. 

any ideas why his phone  isn't auto connecting? 

thank you 

[caesarome]

No idea why it is happening but is the phone set to abroad:

Apple:
Settings > Mobile Service > SIM Applications > Make sure this is set to Abroad..

Android:
Sky Menu App or SIM toolkit > Roaming > Make sure this is set to Abroad.

[Zoe411]

Thank you for replying, however unfortunately  that hasn't worked - it's a complete mystery! 
he's getting around it by self selecting the network I'm auto routed too every 24hrs. Bizarre! 

thanks again