I have a couple of remote devices which have been running happily for many years, on old Vodafone SIM cards in SIM800 modules. 

Yesterday at what looks like exactly 12am, they stopped connecting to the network. 

Wondering if anyone might know if there's something that has changed with the One 2G/GPRS network? The devices are in different locations so it's not the local tower, they both stopped connecting at the same time so it's more likely a network issue. 

Logs also show both devices reported an HTTPACTION 601 which is an AT response code for network error, before they signed off permanently. 

They didn't turn off GPRS did they? 😔