I just got back from Apple Store and they swapped out my phone for a new one and the problem was fixed!!!
I would suggest doing these steps first before you go to Apple Store:
1) Call your cell company to debug first. Apple is going to say since it’s cell service issue and it’s not Apple problem. Cell company is going to go through list of debugging issues (reset network settings, etc) to see if that fixes your issues. If that doesn’t fix, continue debugging steps below.
2) Do a screen record of your phone dropping the cellular connection as evidence of you having issues just in case you’re in the Apple store and you can’t reproduce the issue.
3) Backup your phone. I used my laptop to backup because it restores much faster that way than going through WiFi.
4) Do a full wipe of your phone and set up your phone as a new phone (don’t restore from backup). This way you can see if your cellular issues are from software or from hardware.
4) Test our your phone and see if you are experiencing same issues.
5) If your cell connection is still dropping, take it into the Apple Store.
Good luck! I feel this is for sure a hardware issue for most people!