[-ajm-]

Since I restored my Xperia Z2 D6503 I've been having a reoccurring issue with my phone not accessing Three's 4G network.

For example, the other day when on train going past Botley in Hampshire (a 4G 1.8GHz area), it connected to 4G after toggling airplane mode. However when I drove up there later to test this I never managed to connect.

At times when I can't connect my network list usually looks like this, https://www.dropbox.com/s/b9mhj48i57...45-01.png?dl=0
The 4G network does not sit at the top.

This afternoon it connected to 4G without my intervention, when I got home I did a network scan and it was at the top of the list, however after toggling airplane mode it has moved further down the list and I am unable to connect.

It seems to be somewhat intermittent.

Anyone got any ideas what is causing this and how to resolve it? I'm at a loss.