I have this problem with my Galaxy S7. I have never head this problem before. I have never had a signal problem. I do not have issues with texting or data use. I simply have people who call me but my phone does not ring and a missed call never shows. I have checked to ensure that they (one is my son away at college) are not blocked. It's really frustrating and has been happening only since the most recent update which I have found problematic at best.