I cannot say for sure but you may need to get a new phone, just because it supports 4G does not mean that it supports VoLTE which is what the networks are switching too exclusively. You will still be able to transmit data, so if like what happens in my household most calls are using apps rather than actual voice calls, then it won’t be a problem, but otherwise you might be out of luck. Here are several articles on what the change actually means and how it might affect your phone:
Hope this helps
//i\\