Scale out not working as expected

AFL Programming
#1

Hello,
I am trying to implement scaling out 50% of the position when a target is hit but i get un expected results.

here is my code

higher=Ref(H,-1);
lower=Ref(L,-1);
dif=higher-lower;
Buy = C>=higher;

//AddColumn(Buy,"Buy");
Filter=C;
//sigScaleOut1=
Sell=0;

buyingPrice=0;
diff=0;
tp=0;
sellingPrice=0;
sellingPrice2=0;
ok=0;
tp1=0;
for (i=0;i<BarCount;i++)
{
	//ok[i]=99;
	if(tp==0 AND Buy[i]==1)
	{
		buyingPrice= BuyPrice[i];
		ok[i]=1;
		tp=1;
		diff=dif[i];
		sellingPrice=lower[i];
		sellingPrice2[i]=lower[i];
		tp1[i]=1;
	}
	else if(tp==1 AND C[i]>=(buyingPrice+diff))
	{
		ok[i]=2;
		Buy[i]=sigScaleOut;
		tp=2;
		sellingPrice=lower[i];
		tp1[i]=1;
	
	}
	else if(tp==2 AND  C[i]>=(buyingPrice+(2*diff)))
	{
		Sell[i]=1;
		tp=0;
		ok[i]=3;
		Buy[i]=0;
	}
	if(C[i]<=sellingPrice OR C[i]<=lower[i])
	{
		Sell[i]=1;
		ok[i]=4;
		sellingPrice=0;
		tp=0;
		Buy[i]=0;
	}
	BuyPrice[i]=buyingPrice;
	
}

SetPositionSize(100, spsPercentOfEquity ); 
SetPositionSize( 50, IIf( Buy == sigScaleOut, spsPercentOfPosition, spsNoChange ) );

when a scaleout signal is triggered the backtester exists un expected number of shares
here is an example
exits

i tried searching and understanding what is different between my code and the offical code on setPositionSIze page but i failed.

Thanks in advance,