Logging from different pc

hello guys yesterday i wanted to continue a match with my friend marco (playnig malifaux module), when i joined his game room on the server, vassal opened the map but i couldn t use my deck , cards were unflippable. we stopped the game cause we didn t find any solution. i played with another connection and with another pc in a friend house.
the server didn t recognize me like a player of the game,then i saw that i was registered on that laptop with a different username in the preferences menu(probably i played another game that i don t remember), i changed it to uniform but actually nothing change.
is there a solution to play from two different pc once started like this? or should they start always the game with the same user and password to play from different device?