I have a very very confuse doubt. Here in my country there are theree companies, all oh them works in the same frecuency, in the same bands. I bought the three sim card, each one, one company, company A works perfect, company B works perfect too, but company C doesnt work....very straged men, I didnt fine the exactly explanation. I went to the company and they dont know what are fu.....happen ha ha ha. If somebody can give some reply I invite him to my country in holiday. I dont know what is happens. Only I thought in something, maybe company C block oneplus 5 phone, but I dont know how they recognized?. I think my IMEI number, in the company said me im crazy, but there are not logical explanation