After gathering all the information about error 630, and passed it onto a friend who's a MS certified systems engineer and has come to the conclusion, this is 100% on your end - this is not client internet or ISP problems. This is load balancing and de-synchronization when going from a peer-to-peer instance back to the hub, the server is rejecting some clients or not re-connecting fast enough to sync back up and that is causing all the error 630s at all these specific points.
There is nothing the people who are suffering from these errors can do to fix the problem, changing settings on routers, port forwarding will not do anything - this is all on Sega's systems engineers to fix, and I suggest this is kept bumped and reports sent to Sega.
Case and Point -
Lobby/Hub areas are dedicated Servers ran by Sega, but the fields etc are Peer to Peer so when you transfer from one field to another, or exit the field and your client has to re-sync back up to Sega's servers....for some people, that isn't being done properly and that is causing the frequent error 630.
This needs to be addressed.