4G tp-link won’t connect abroad

[Ry45]

Hi - has anyone been able to solve the issue of the tp-link 4g WiFi working while abroad? It works seamlessly in the UK but I am unable to connect while I am in Greece. 

*I have turned on roaming

*I have reset the device

*I have active data available (via a top up sim)

not sure what else to try as it shows full connection on the device but nothing loads when connected to it.

[Mustrum]

What model, where did you get it, is it locked to a UK mobile provider?

So many questions, what sim are you using, which provider?