LTE Flaky after replacing battery and Lightning Connector/ MIC

Hi,

Now that I have replaced my battery and microphone/lightning connector assembly, my cellular connection seems to be very flaky. About 90% of the time I can't make outgoing calls over cellular. However, I'm getting very old short message text messages from a year ago. I have checked the time and its set correctly. I can make outgoing calls over wifi, just not cellular. Data connection over cellular is also not working. It does show LTE bars, switching from 1X and 3G sporadically.