RT-AC68U + Merlin 380.65_2 - PPTP from inside network doesn't work

[klosz007]

Hello,

I have just upgraded firmware on my RT-AC68U from Merlin's 380.65 to 380.65_2.
Then I immediately realised that my Synology NAS couldn't initialize VPN PPTP tunnel to boxpn.com VPN service anymore - tunnels couldn't connect reporting user authentication error.
Initially, I thought something went wrong with VPN service itself but since this had happened immediately after upgrading my router, I decided to downgrade back to 380.65 and then everything went back to normal.

Any idea what may be causing this ?

Thanks,
Zbyszek