Transferred my number and old Samsung S7 from U.S. Cellular on 11/22. 4G data and texting worked soon after installing Ting SIM and configuring APN, but calling/receiving calls has not. I have been able to call/receive calls during the evening/morning but not during the day. My phone always says that it has no bars, but when I can call/receive a call they magically appear and I have full service. Otherwise they are gone. I do still have 4G or "E" data and the ability to text, even MMS.
Any ideas on what to try?