I can't make an outgoing call and can't call me also, if I am on 4g. But the strange thing is, it is exist only with one mobile provider (here in my country Hungary). We have 3 provider:Telekom, Vodafone, Telenor. Telenor won't work. If I change to 3g everything is work like a charm with this provider too. I tried 3 different Mi MIX 2 with chinese stable and developer and EU developer rom too. Same result. Any solution? Thank you.