Why doesnt my internet work in mexico?

[AC Question]

i have the unlimited plan and the north american plan from tmobile on my iphone 6. So i have unlimited internet and messages and calls in mexico. But my internet says 3g but my internet doesnt work untile the VPN is connected. So i didnt know so I deleted the VPN off my iphone but it stills 3g but my internet doesnt work and i have good signal.

 

[TechnoGamingPro]

Internet works mainly in UK or US, Im not sure for Mexico

Mountain Dew And Doritos=Mlg