Sometimes Mapmixer does not create map scripts due to Windows security restrictions.
@SaiFeX, I'm not sure if I understood correctly, so please ask again if I don't answer your question properly.
The default MMH55 maps that come with the mod are not LAN compatible. The reason is unknown (but scripts are activated).
To be 100% sure a map is LAN compatible, create it via this manual. Then distribute it to all players and try to start a game.
IMPORTANT: After creating the map, go to <game folder> / DATA and delete the file named index.bin and the folder named RMGTemp. These are corrupted files that can desync a running game or prevent a multiplayer game from starting.