Where can I set the SMS center number of Nubian mobile phone?

SMS-Settings-SMS center number. Default SMS center number after inserting a mobile phone card.

Z5S has just started for three days. I am in Chengdu. I went to Ya 'an yesterday, which means the area code has changed. You need to add the Chengdu area code to call Chengdu. Then on the way to the highway, I suddenly couldn't send a text message. I could accept a text message, but I couldn't send it. I'll contact 10086 immediately and say it's a problem with the number setting of the SMS center. It's strange that I changed my mobile phone and never touched the number of the SMS center. Why did the SMS center number change for no reason? Ok, then 10086 re-sent a short message center number, and I said reset it. . . . . . As a result, Z5S didn't have this option at all, and the answer after the call was that the number setting of SMS center was blocked! ? ! ? ! ? ! ? ! So what should I do? The solution given by customer service is to set it on another mobile phone. I want to ask, is it necessary to set the SMS center number on another mobile phone that is not another mobile phone? The second question is about GPS. Z5S GPS can't find any stars at all. I used Baidu map, Kai Lide, Gao De, Tiger, WeChat location and QQ location. None of these softwares can make GPS search satellites. It always shows that the satellite is still searching after 1 hour. I am outdoors in a very empty place, and the sun is shining. . . . . Can the official give an explanation? I have this problem with both Z5s. . . .