//////////////////////////////////////////////
//        RemoteXY include library          //
//////////////////////////////////////////////

// RemoteXY select connection mode and include library
#define REMOTEXY_MODE__ESP8266_HARDSERIAL_CLOUD

#include <RemoteXY.h>

// RemoteXY connection settings
#define REMOTEXY_SERIAL Serial
#define REMOTEXY_SERIAL_SPEED 115200
#define REMOTEXY_WIFI_SSID ""
#define REMOTEXY_WIFI_PASSWORD ""
#define REMOTEXY_CLOUD_SERVER "cloud.remotexy.com"
#define REMOTEXY_CLOUD_PORT 6376
#define REMOTEXY_CLOUD_TOKEN "6602cbde8b07ca2f3316aa5ff4580fb9"

// RemoteXY configurate 
#pragma pack(push, 1)
uint8_t RemoteXY_CONF[] =
  { 255,2,0,0,0,30,0,10,13,1,
  2,0,22,14,22,11,2,26,31,31,
  79,78,0,79,70,70,0,1,0,27,
  72,12,12,2,31,88,0 };
 
// this structure defines all the variables and events of your control interface
struct {

    // input variables
  uint8_t switch_1; // =1 if switch ON and =0 if OFF
  uint8_t button_2; // =1 if button pressed, else =0

    // other variable
  uint8_t connect_flag;  // =1 if wire connected, else =0

} RemoteXY;
#pragma pack(pop)

/////////////////////////////////////////////
//           END RemoteXY include          //
/////////////////////////////////////////////

#define PIN_SWITCH_1 0
#define PIN_BUTTON_2 3

void setup()
{
  RemoteXY_Init ();
 
  pinMode (PIN_SWITCH_1, OUTPUT);
  pinMode (PIN_BUTTON_2, OUTPUT);
 
  // TODO you setup code
 
}

void loop()
{
  RemoteXY_Handler ();
 
  digitalWrite(PIN_SWITCH_1, (RemoteXY.switch_1==0)?LOW:HIGH);
  digitalWrite(PIN_BUTTON_2, (RemoteXY.button_2==0)?LOW:HIGH);
 
  // TODO you loop code
  // use the RemoteXY structure for data transfer
  // do not call delay()

}

Why use a while loop ? Why create float k1 if you never use it ?

void Calabrate(){
  Serial.println("1:Place Probe into pH7 calibration fluid, open serial ");
  RemoteXY_Handler ();
  while (strcmp (RemoteXY.XY_input, "exit")!=0){
    RemoteXY_Handler ();
    PH_Anlog_Sum=0;
 
 
    PH_Anlog_Avg=PH_Anlog_Sum/10;
    phValue=PH_Anlog_Avg*K*5/1024;
    Serial.println("    ");
    Serial.print("PH_Avg (cal mode):");
    Serial.println(phValue);
    dtostrf (phValue,4 ,2, RemoteXY.ph_val);
    Konstant=((7*1024)/(PH_Anlog_Avg*5));
    Serial.print("To achive pH 7, K Konstant needs to be : ");
    Serial.println (Konstant);
    dtostrf (Konstant,4 ,2, RemoteXY.PH_correction);
    float k1 = atof (RemoteXY.XY_input);
  }
}

Show your code, ideally a small code which demonstrates the problem and nothing else.