@Gort thanks for the info. I think CHAP is the only authentication type I haven't yet tried, but I'll give that a shot. Nothing else has worked so far. TP-Link advised me to use PAP so I've stuck to...

@David-TP device details below.

@David-TP APN settings below.

@David-TP additional screen for the mobile settings

@David-TP authentication type is currently set to Pap but I've tried all the other options too. I'm running the latest firmware (1.1.3)

I've just been attempting to set up a new X50-5G using an EE sim that I've been using successfully in another router for years using the settings below: Name: ee internet (lower case) user name:...