Range not behaving as expected

Goodmorning all. 

I'm trying to create a "dynamic" range using ArrayMax/Min - as each new bar comes in (and assuming some other criteria are met) the range extends in length - to achieve this I have elected to create a variable, the value of which changes upon each new candle (and some other criteria), and placed this into the count parameter in place of a fixed value. My ArrayMin range appears to be working OK but not the ArrayMax, even though both functions are pulling their data from the same source.

Just so we're all on the same page:
1. My array index positions and "ï" match - 0 is the oldest bar on the chart.
2. My terminal options are set to have a Max of 5000 candles in the history and 5000 on the chart; as i'm printing my own candles i turn off the built in bars/candles.
3. I've been testing this on a bar by bar basis - by manually incrementing expression2 (starting with candle 4 - so you'll need to scroll all the way to the left) of the for loop on a weekly EUR/USD chart and have left the attached code in this state so you can see for yourselves - should you need to look. I've highlighted the for loop in question.

Assuming your set-up matches that which i have stated above you should see the following:
1. [0] is the "last" (in this case also the first) swing point.
2. [1] is the highest candle on the chart.
3. [3] is the lowest candle on the chart.
4. i=[4].
5. The number of bars in either range is 4 (derived by the calculation: int Bars_In_Range=i-Last_Swing).
6. The range Low is [3].
7. The range High is [5] where i'm expecting it to be [1] - This is particularly confusing to me as [5] hasn't even been printed on the chart yet.
8. If you manually enter 4 into the ArrayMax "count" parameter then the range does what i'm expecting it to and reports [1] as the range high.

Apologies if that's a little long winded i just wanted to make sure i gave you the correct info.  

Here's the code:

//+------------------------------------------------------------------+
//|                                   Heiken Ashi Trend Detector.mq4 |
//|       Copyright © 2016 Carl Carver Software. All Rights Reserved |
//|                                          carl_carver@hotmail.com |
//+------------------------------------------------------------------+

//Indicator Basic Properties
#property copyright "Copyright © 2016 Carl Carver Software. All Rights Reserved."
#property link      "carl_carver@hotmail.com"
#property version   "1.00"
#property description "Heiken Ashi Trend Detector"
#property strict
#property indicator_chart_window
#property indicator_buffers 11

//Indicator Format Properties
//HA Properties
#property indicator_color1 clrBlack
#property indicator_color2 clrRed
#property indicator_color3 clrLimeGreen
#property indicator_width1 1
#property indicator_width2 1
#property indicator_width3 3
#property indicator_width4 3

//Swing Properties
#property indicator_color5 clrBlack
#property indicator_color6 clrBlack
#property indicator_color7 clrBlack
#property indicator_color8 clrBlack
#property indicator_color9 clrBlack
#property indicator_color10 clrBlack
#property indicator_width5 2
#property indicator_width6 2
#property indicator_width7 2
#property indicator_width8 2
#property indicator_width9 2
#property indicator_width10 2 

//User Inputs
//HA Candle Properties                                                      
input color Shadow=clrBlack;
input color Bear_Body = clrRed;
input color Bull_Body = clrLimeGreen;

//Buffer Arrays
//HA Buffers                                               
double HA_High_Buffer[];
double HA_Low_Buffer[];
double HA_Open_Buffer[];
double HA_Close_Buffer[];

//Swing Buffers   
double Swing_1_Buffer[];    //Wingding symbol code: 140 - On-screen symbol: 1
double Swing_2_Buffer[];    //Wingding symbol code: 141 - On-screen symbol: 2
double Swing_3_Buffer[];   //Wingding symbol code: 142 - On-screen symbol: 3
double Swing_4_Buffer[];   //Wingding symbol code: 143 - On-screen symbol: 4
double Swing_HL_Buffer[];   //Wingding symbol code: 144 - On-screen symbol: 5
double Swing_HH_Buffer[];   //Wingding symbol code: 145 - On-screen symbol: 6

//Counter Buffer
double Counter_Buffer[];

//Pre-program buffer implementation and mapping
void OnInit(void)
  {
   IndicatorDigits(Digits());

//HA Buffers
   SetIndexBuffer(0,HA_High_Buffer);
   SetIndexStyle(0,DRAW_HISTOGRAM,0,1,Shadow);
   SetIndexDrawBegin(0,0);
   SetIndexLabel(0,"HA High");

   SetIndexBuffer(1,HA_Low_Buffer);
   SetIndexStyle(1,DRAW_HISTOGRAM,0,1,Shadow);
   SetIndexDrawBegin(1,0);
   SetIndexLabel(1,"HA Low");

   SetIndexBuffer(2,HA_Open_Buffer);
   SetIndexStyle(2,DRAW_HISTOGRAM,0,3,Bear_Body);
   SetIndexDrawBegin(2,0);
   SetIndexLabel(2,"HA Open");

   SetIndexBuffer(3,HA_Close_Buffer);
   SetIndexStyle(3,DRAW_HISTOGRAM,0,3,Bull_Body);
   SetIndexDrawBegin(3,0);
   SetIndexLabel(3,"HA Close");

//Swing Buffers   
   SetIndexBuffer(4,Swing_1_Buffer);
   SetIndexStyle(4,DRAW_ARROW);
   SetIndexArrow(4,140);
   SetIndexLabel(4,"Rule 1");

   SetIndexBuffer(5,Swing_2_Buffer);
   SetIndexStyle(5,DRAW_ARROW);
   SetIndexArrow(5,141);
   SetIndexLabel(5,"Rule 2");

   SetIndexBuffer(6,Swing_3_Buffer);
   SetIndexStyle(6,DRAW_ARROW);
   SetIndexArrow(6,142);
   SetIndexLabel(6,"Rule 3");

   SetIndexBuffer(7,Swing_4_Buffer);
   SetIndexStyle(7,DRAW_ARROW);
   SetIndexArrow(7,143);
   SetIndexLabel(7,"Rule 4");

   SetIndexBuffer(8,Swing_HL_Buffer);
   SetIndexStyle(8,DRAW_ARROW);
   SetIndexArrow(8,144);
   SetIndexLabel(8,"Sw. Higher Low");

   SetIndexBuffer(9,Swing_HH_Buffer);
   SetIndexStyle(9,DRAW_ARROW);
   SetIndexArrow(9,145);
   SetIndexLabel(9,"Sw. Higher High");

//Counter Buffer
   SetIndexBuffer(10,Counter_Buffer,INDICATOR_DATA);
   SetIndexStyle(10,DRAW_LINE,STYLE_SOLID,1,CLR_NONE);
   SetIndexLabel(10,"Bar #");
  }

//+------------------------------------------------------------------+
//| Globalscope Custom Function and Variable Declarations            |
//+------------------------------------------------------------------+  
//Some code here

//+------------------------------------------------------------------+
//| Main program                                                     |
//+------------------------------------------------------------------+
int OnCalculate
(
 //Standard bar price and data arrays
 const int rates_total,
 const int prev_calculated,
 const datetime &time[],
 const double &open[],
 const double &high[],
 const double &low[],
 const double &close[],
 const long &tick_volume[],
 const long &volume[],
 const int &spread[]
 )
  {

//Price Arrays
   ArraySetAsSeries(open,false);
   ArraySetAsSeries(high,false);
   ArraySetAsSeries(low,false);
   ArraySetAsSeries(close,false);
   ArraySetAsSeries(time,false);

//Heiken Ashi Arrays
   ArraySetAsSeries(HA_High_Buffer,false);
   ArraySetAsSeries(HA_Low_Buffer,false);
   ArraySetAsSeries(HA_Open_Buffer,false);
   ArraySetAsSeries(HA_Close_Buffer,false);

//Swing Arrays
   ArraySetAsSeries(Swing_1_Buffer,false);
   ArraySetAsSeries(Swing_2_Buffer,false);
   ArraySetAsSeries(Swing_3_Buffer,false);
   ArraySetAsSeries(Swing_4_Buffer,false);
   ArraySetAsSeries(Swing_HL_Buffer,false);
   ArraySetAsSeries(Swing_HH_Buffer,false);

//Counter Array
   ArraySetAsSeries(Counter_Buffer,false);

//Heikin Ashi Candle Variables           
int
i=0,
Lookback=IndicatorCounted();

double
HA_Open,
HA_High,
HA_Low,
HA_Close;

//Swing variables
int
Last_Swing=0,
Bars_In_Range=0,
Swing_Rule=0,
Range_Low=ArrayMinimum(HA_Low_Buffer,Bars_In_Range,i),//Outputs shift of range low
Range_High=ArrayMaximum(HA_High_Buffer,Bars_In_Range,i); //Outputs shift of range high

//Error Check - Sufficient candles on chart to complete calculations? 
   if(Lookback<1) return(-1);

//Setting The First Candle and Swing Point
   for(i=0; i<1; i++)
     {
      if(close[i]>open[i] || close[i]<open[i])
        {
         //Update the counter on each iteration of the loop - in this case once
         Counter_Buffer[i]=i;
         //Candles print as follows
         HA_Low_Buffer[i]=low[i];
         HA_High_Buffer[i]=high[i];
         HA_Open_Buffer[i]=open[i];
         HA_Close_Buffer[i]=close[i];
         //Set the first swing point on the first candle on the chart
         Swing_1_Buffer[i]=HA_Low_Buffer[i];
        }
     }

//Setting the first 3 HA candles - necessary so to avoid an "array out of range" error during the swing calc
   for(i=1; i<4; i++)
     {
      //Update the counter on each iteration of the loop - in this case thrice
      Counter_Buffer[i]=i;
      //Establish current HA OHLC on each iteration of the loop
      HA_Open=(HA_Open_Buffer[i-1]+HA_Close_Buffer[i-1])/2;
      HA_Close=(open[i]+high[i]+low[i]+close[i])/4;
      HA_High=MathMax(high[i],MathMax(HA_Open,HA_Close));
      HA_Low=MathMin(low[i],MathMin(HA_Open,HA_Close));
      //Candles print as follows:
      HA_Low_Buffer[i]=HA_Low;
      HA_High_Buffer[i]=HA_High;
      HA_Open_Buffer[i]=HA_Open;
      HA_Close_Buffer[i]=HA_Close;
     }

//Main HA candle and swing detection calculations and loop
   for(i=4; i<=4; i++)
     {
      //Update the counter on each iteration of the loop - in this case on every new candle
      Counter_Buffer[i]=i;
      Bars_In_Range=i-Last_Swing;
      //Establish current HA OHLC on each iteration of the loop
      HA_Open=(HA_Open_Buffer[i-1]+HA_Close_Buffer[i-1])/2;
      HA_Close=(open[i]+high[i]+low[i]+close[i])/4;
      HA_High=MathMax(high[i],MathMax(HA_Open,HA_Close));
      HA_Low=MathMin(low[i],MathMin(HA_Open,HA_Close));
      //Candles print as follows:
      HA_Low_Buffer[i]=HA_Low;
      HA_High_Buffer[i]=HA_High;
      HA_Open_Buffer[i]=HA_Open;
      HA_Close_Buffer[i]=HA_Close;

Comment
      ("i: ",i,
       "\nBars: ",Bars,
       "\nLast Swing: ",Last_Swing,
       "\n",
       "\nBars in Range: ",Bars_In_Range,
       "\ni-Last Swing: ",i-Last_Swing,
       "\n",
       "\nRange_Low: ",Range_Low,
       "\nRange_High: ",Range_High);
     }

//End of program  
   return(rates_total);
  }

As always, thanks to anyone that can advise what it is i'm doing wrong. 

Thanks, 

Carl.