Bug in Positions.Find

I have an algo that creates market orders and then closes the positions when some criteria is met.

If I create the positions using the following : var result1 = ExecuteMarketOrder(TradeType.Sell, Symbol, 10000, "SellPosition");

Then close using  

Position SellPosition = Positions.Find("SellPosition", Symbol);

var result1 = ClosePosition(SellPosition);

Everything works as expected can backtest over 7 years all positions open closed as expected.

However if I create the positions using 

var result1 = ExecuteMarketOrder(TradeType.Sell, Symbol, 10000, "SellPosition",10,10); 

So the position has a stop loss and tp, everything starts ok but after the 3rd call to Positions.Fing does not find a position even though the position was succesfully created.

Just to be clear that is the only line that changes adding a tp and sl, the remainder of the code is exactly the same.

I have also tried by fully populating the method ie (TradeType.Sell, Symbol, 10000, "SellPosition",10,10,3,"some comment"); 

this also fails the only call that works is ExecuteMarketOrder(TradeType.Sell, Symbol, 10000, "SellPosition");

I would be greatfull if you could fix this rather annoying bug.