CopyHigh does not update history of lower timeframe

[Rene Balke]

Hey,

right now i experience a really strange behavior in one of my EAs. I use the code below to calculate a range between two times. It is called in a funcion that is called in the OnTick(). I use the exact same EA on the EURUSD (5 min chart) and the USDJPY (1 min chart). When i start the EA everything works fine for that day (for both symbols). But the next day the EA attached to the 5 min EURUSD chart is unable to receive the 1 min history. The MT5 Terminal is running on a VPS so there is no interruption. The weird thing is that GetLastError() returns 0 on every tick. The USDJPY EA works fine on this day, too.

Did someone experience this before and is able to provide help? Would be highly appreciated.

Greetings, René 

   ResetLastError();
   double highs[], lows[];
   int resHigh = CopyHigh(_Symbol,PERIOD_M1,startTime,endTime,highs);
   int resLow = CopyLow(_Symbol,PERIOD_M1,startTime,endTime,lows);

   if(IsDebug){
      Print("res high: ",resHigh,", res low: ",resLow);
      Print("size highs: ",ArraySize(highs),", size lows: ",ArraySize(lows));
      Print("error is: ",GetLastError());
      Print("syncronized: ",SymbolIsSynchronized(_Symbol));
   }
   
   if(ArraySize(highs) <= 0 || ArraySize(lows) <= 0) return;

   rangeHigh = highs[ArrayMaximum(highs)];
   rangeLow = lows[ArrayMinimum(lows)];
   rangePoints = rangeHigh - rangeLow;

   if(IsDebug) Print("range high: ",rangeHigh,", range low: ",rangeLow);

[Rene Balke]

Update: I managed to solve the problem with the CheckLoadHistory() function from this thread: https://www.mql5.com/en/docs/series/timeseries_access

But I still don't really understand the problem with my old code. The CopyHigh/CopyLow call should initiate the download and build process as it is written in the documentation. So on the next tick or the tick after ... there should be data available. That is pretty much the same thing that CheckLoadHistory() does, because it returned 2 in my case.

Maybe someone can help me here and provide an explanation. :)