@golguin: looks like you were right about the parries working as intended; he certainly parried your slash with that giant cannonball quite well!
Of course the parries work as intended. Never have an issue in my world in PVE. The connection issues are something else entirely.
Also, it seems PVP is over for me before it began. All my bell maidens and bosses are dead in the nightmare area so PVP has been cut off forever in this playthrough. Anyone that I happen to catch in PVP is simply passing by on their way to the boss. Once they kill their maidens and boss the cut off people will happen for them as well.
It seems that the only solution is to go into NG+ and leave all optional bosses alive and never complete the Nightmare areas. PVP is essentially fucked for Bloodborne without doing that.