This seems to only happen when in any dungeon, more often than not. Where, we get about half way through a dungeon, and everything freezes in the middle of combat, followed by disconnecting.
Only reason I know it's the whole party is due to the fact that we can still chat for the one minute before getting disconnected, with them wondering what's going on before the boot.
Then it happened another time with a static group of people from my LS and we all experienced it again, to confirm that it's not just me. It makes it hard to continue a story quest with this happening.