Mobile data doesn't work but it is on

In my iPhone SE mobile data doesn't work but it is on (phone shows 4G on top left), data roaming is on as well. Apps that require mobile internet does not load anything. When I open Safari, it says ''Could not activate mobile data network. You are not subscribed to a mobile data service'' but I have internet in my tariff plan. I called my carrier, they said that the problem is in phone and from their side everything is fine. I have restarted phone many times and tried to take out SIM card and put it back in, too. Just updated iOS and carrier settings, still does not work. Any tips?