Check your NAT settings in the game. If the NAT color is red or it says "NAT Strict", then try these steps:
1. Log into your router and make sure that UPnP is turned on. This fixed my connection issues on PS4 last night.
2. Open up the TCP and UDP ports that Ubisoft is using. I don't know them off the top of my head, you can probably Google them real fast.