Switching to P2P does not seem to take.

[Zlartibartfast]

I'm not clear on the specific steps you took, so forgive me if I'm stating what you already know (perhaps others reading this will not know). You have to be out of a session to make changes to your Network Settings. Also, since the ARS is relatively new, I've been selecting "Prefer lowest latency path" though I'm almost always online with the same person, most likely always in peer to peer mode.