Hi again,
I finally found out! 
After setting the TeamId, you must update the listener.
So, in BeginPlay() for example:
SetGenericTeamId( FGenericTeamId( 1 ) );
UAIPerceptionSystem::GetCurrent( GetWorld() )->UpdateListener( *PerceptionComponent );
The issue was that the perception component of each AI was registered to the global perception system when the team id of each enemy was not set.
Hope this helps!