I have a Samsung Galaxy Note 4 phone with service from Tmobile. Two days ago, I kept getting notifications from Visual Voicemail saying that it was having trouble connecting with its server. At the end of the day, I noticed that a number of calls had come in on voice mail but I’d never heard the phone ring. I asked my wife to call my phone and her call went right to voice mail. I tried calling out and it returned a message that said call not sent. In the notification line at the top of the phone screen, I noticed crazy activity. The icon for the wifi connection would be on, then it would go away and a 4G icon would come on and then the llittle triangle that indicates connection to the mobile phone network would be marked with an X and no bars. Then, back and forth, rinse, wash and repeat. When I checked my Smart Network Switch, it was on, but then suddenly it would gray out accompanied by a message that read, “This feature is turned off. No SIM card has been inserted.” When I checked Wi-Fi Calling under More Networks, it read, “ER06 - SIM not ready.” So I assumed that my SIM card had been corrupted somehow. I went into a T Mobile store yesterday morning, and the attendant gave me a new SIM card, did some kind of reset on the phone as well (not a full factory reset) and said it could take up to 24 hours for everything to work again. It is 24 hours later, and things still haven’t resolved. I cannot make a call out or receive a call or text (I tried to get a text to authenticate my credentials to enter this site and did not receive a text, so I went to security questions to get in). I have read in some other forums that the solution is to have customer service reset the IHLR (Integrated Home Location Register) settings. Is that a thing? Please let me know.