My mobile data is not working, it only works with vpn enabled and in most apps

[AC Question]

Hey all,

I have a big problem with my mobile phone. My connectivy thing in the upper shows an exclamation mark and says 3g. I can use whatsapp and other apps like clash of clans. But when I use a browser it all doesn't work. It only works when I am connected to a vpn. I am using a one plus 3 and my subscription is form Telfort(the Netherlands). I hope you guys can help me!~

Yours sincerely,

Wouter van Dijk