[Pottus]

That is strange indeed, it almost sounds like another CP is being created overwriting your reference but this code here
will delete any CP's associated with the player.

pawn Код:

new amountCPs = CountDynamicCPs();
    for(new i; i < amountCPs; i++)
    {
        if(Streamer_GetIntData(STREAMER_TYPE_CP, i, E_STREAMER_PLAYER_ID) == playerid) DestroyDynamicCP(i);
    }

Are you absolutely sure your looping through all of them? If you are losing your reference (t_PlayerJob[playerid][deliveryCheckpoint] == _cpid) does the CP get triggered when you enter it at all and what is the initial CP ID when created and CP ID that is getting triggered?