Possible CDMA antenna issue?

DEVICE: Note4 (Verizon) SM-N910V

BACKGROUND: I recently had my phone repaired by one of those mall shops, due to a broken charging port/ broken home button. While they were certainly friendly, and did repair the issue, I noticed my "tabs" soft button no longer worked. I brought it back for the warranty work, and it was fixed without any fuss. Another issue has developed and it seems related to that general area of the phone.

PROBLEM: When placing or receiving a call, my data drops to 1x. I suspect this is due to the phone using 4g LTE to connect to voice instead of using CDMA. I'm hoping for the antenna to be disconnected. Looking for help in finding where the CDMA antenna connector is. I'd also be glad to hear any suggestions about what the issue maybe.

Thank you for your time.