This didn't solve my issue by any means but helped with how often I get network issues with Xbox One Connection Issues. I also do not disconnect from PvZ GW as often as I did. On your home router if you are able to Setup Port Triggering or Port Forwarding you can add these ports:
These are basic Xbox One Ports:
TCP: 53, 80, 3074
UDP: 53, 88, 500, 3074, 3544, 4500
Just adding these triggers will help with Xbox One behind NAT. EA does use 80, 53, and 3074 for but not for the PvZ GW multiplayer connections. Sorry, trying to get those ports from EA as we speak.
Ports 80, 53, 3074 may fix EA Origins Authentication issues. If that is what is causing your issue.
(Opening these ports help fix issues with Xbox Live Voice Issues and Destiny partially)
Hope it works for you.
