Just got this game going again and got my brother instantly hooked as well *but*; while we have no issues at all getting a multiplayer game started, the games frame rate will drop on both computers down to nothing. It's still playable, but the trains don't move; they just sort of jump along the track.
Neither of us have any issues in single player mode.
Both PC's are relatively new, running W10 64bit, 8gb ram, I5 6600k, GTX960 and we're on a gigabit switch.
I'm at a loss as to why it would be any different in a multiplayer game so if anyone's got any ideas they'd be much appreciated. We tried SM's Railroads! hoping it would be similar but with better graphics - it's not.