Is my network selector goosed?

[davermurff]

My S6 Edge is set to the LTE setting in Mobile Networks but whenever the phone goes to sleep mode or is switched off by closing the case, it seems to be unable to connect to 4G when go to use it next unless I physically change from the LTE setting to one of the other 2 options then back to LTE. The 4G icon on the top of the screen only shows once I have done this. Has anyone come across this issue and is it fixable or would it be better to just upgrade to another phone?
Also occasionally the screen shows a vertical purple line the full height of the screen. This doesn’t appear to be causing an issue but maybe it is a sign of pending screen failure. Any ideas on this would be much appreciated.
Thanks,
Dave.

 

[B. Diddy]

Welcome to Android Central! What's the exact model number of the phone, and which carrier are you on? Are you sure the APN settings are correct?

 

[davermurff]

Hi B. Diddy,
The model number is SM-G925F and the carrier is Three. As far as I can tell the phone is on the latest update and has never been dropped or soaked . As for the APN settings you will have to enlighten me further.
Thanks for your reply.
PS , forgot to mention I am in the UK.

 

[B. Diddy]

Make sure the APN settings are correct:

Getting started - Connecting to the internet. - Three
https://www.androidcentral.com/what-apn-and-how-do-i-change-it

 

[davermurff]

Many thanks, will give it a go and see how I get on.
Dave.