My Device Doesn't Go In 4g And Wifi Is Supeslow

Jan 11, 2018
Hello i'm from italy and bought this xiaomi redmi note 4 4G 10x cores xelio version.
It never goes in 4g even if there is cover, and also when connecting in wifi is very slow.
According to vodafone italy and this device, it should go up to 150Mb/s b3-b7 are supported.
Well, it's not happening, i wonder if is miui 9 that has some connectivity bug? I have the latest weekly build.
Any way to solve?