но у меня почему то одна единственная стрелка(на покупку) за всю историю

Вы наверное не тот индикатор загрузили.

//+------------------------------------------------------------------+
//|                                                     RSICross.mq4 |
//|                                              Copyright 2021, AM2 |
//|                                      http://www.forexsystems.biz |
//+------------------------------------------------------------------+
#property copyright "Copyright 2021, AM2"
#property link      "http://www.forexsystems.biz"
#property version   "1.00"
#property strict
#property indicator_chart_window

#property indicator_buffers 2

input int RSI=7;
input int Num=3;
input int Level=30;
input int Count=666;

double up[],dn[];
//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int OnInit()
  {
//--- indicator buffers mapping
   SetIndexStyle(0,DRAW_ARROW,0,1,Aqua);
   SetIndexArrow(0,233);
   SetIndexBuffer(0,up);

   SetIndexStyle(1,DRAW_ARROW,0,1,Red);
   SetIndexArrow(1,234);
   SetIndexBuffer(1,dn);
//---
   return(INIT_SUCCEEDED);
  }
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
double PointPrice(int type,int k=0,int n=0)
  {
   int num=0;

   double pr=0;

   for(int i=k; i<Count; i++)
     {
      double rsi1=iRSI(NULL,0,RSI,0,i);
      double rsi2=iRSI(NULL,0,RSI,0,i+1);

      if(rsi1>Level && rsi2<Level && type==0)
         num++;

      if(rsi1<100-Level && rsi2>100-Level && type==1)
         num++;

      if(num==n)
        {
         pr=Close[i];
         break;
        }
     }

   return(pr);
  }
//+------------------------------------------------------------------+
//| Custom indicator iteration function                              |
//+------------------------------------------------------------------+
int OnCalculate(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[])
  {
//---
   for(int i=0; i<Count; i++)
     {
      double rsi1=iRSI(NULL,0,RSI,0,i);
      double rsi2=iRSI(NULL,0,RSI,0,i+1);

      if(rsi1>Level && rsi2<Level && PointPrice(0,i,1)<PointPrice(0,i,2) && PointPrice(0,i,1)<PointPrice(0,i,Num))
        {
         up[i]=low[i];
        }
      if(rsi1<100-Level && rsi2>100-Level && PointPrice(1,i,1)>PointPrice(1,i,2) && PointPrice(1,i,1)>PointPrice(1,i,Num))
        {
         dn[i]=high[i];
        }
     }

//--- return value of prev_calculated for next call
   return(rates_total);
  }
//+------------------------------------------------------------------+