Trouble with blackfish and waypoint

[Neflax 2]

Hi, after unsuccessful several hours of research on internet and in-game test, I thought that I make a post about this in the hope someone help me figure out what's going on.

In the devellopement of a little script for a driver IA in a blackfish to turn around a point on map with the player in gunner, I ran into some sort of unexplained things.

So there is my last code :
 

player onMapSingleClick "if (_shift) then {
	_group = group player;
	for '_i' from count waypoints _group - 1 to 0 step -1 do
	{
		deleteWaypoint [_group, _i];
	};
	_myWaypoint = _group addWaypoint [_pos, -1];
	_myWaypoint setWaypointType 'LOITER';
	_myWaypoint setWaypointLoiterRadius 700;
	_myWaypoint setWaypointLoiterType 'CIRCLE_L';
	_myWaypoint setWaypointLoiterAltitude 500;
	_group setCurrentWaypoint _myWaypoint; // I have in mind this line is maybe too much, but we never know...
	};"

so the script work, but IA "accept" the waypoint in some conditions. And here are those conditions :

I need in the editor to create a blackfish with crew with the player already in gunner position.

Don't work If the player are pilot and change seat after. The IA don't follow the waypoint and act like he don't exist.
The change of leader (IA or player) change nothing in all case. (I change with the command "selectLeader").

And when I'm under these conditions, I can't change seat.

These more : when I setup the driver to be a playable Units and the gunner the player,  the moment I change unit (so i'm driver) I can change seat, but the moment I change seat, I can't change seat again but IA continue to follow waypoint.

So if someone have a detailled explanation and/or a way to prevent this problem I'm all hear.

PS - English is not my first language so if something are unclear, don't hesitate ask me to reformulate or give more explanation.