This will happen if one person is running all assassins.
F = front line melee unit. R = ranged unit. A = Assassin.
If the game starts off like this:
Team 1: 0000000 00RRR00 000FF00
Team 2: 0000000 0000000 AA000AA
Then the assassing will jump behind the ranged units, and the front line units sometimes get stuck and don't know they need to go around to the back of their own team to attack the assassins.
That's literally how it works in regular league so it must be an intended feature.
This is a non-crowded scenario, lol. :)) If the F+ R team is cornering and the A team is going full assa, the of the A team members will not attack because of the crowding factor. What you describe there is not a bug. The assassins are supposed to attack the furthest target. Also, once the assassins uncloak and start the fighting, the F units should start to respond. I haven't encountered F+R teams where those F guys didn't start to pound my A guys... and I played quite alot of it. :)
