Honeywell SS495A hall sensor problem reading

Other Hardware Sensors
7

Thank you for your replies. I stripped down my entire project to only the hall sensor and the flowmeter. I also stripped down my code.

But the problem still occurs, and it only occurs when I replace the type hall sensor, with my old hall sensor (latching melexis US 1881) it worked just fine.

My rpm count raises randomly without any magnet in the neighbourhoud. I'm thinking that the problem have to do with the different types of hall sensor latching/ linear. But I don't know how to solve this.

volatile float rpmHV;
volatile float flowHV;
volatile float rpmTRV;
volatile float flowTRV;
volatile float rpmTAV;
volatile float flowTAV;

int HVmillis=500;
unsigned long millishv;

void setup()
{
    attachInterrupt(1, rpm_fun, RISING);
  rpmHV = 0;
  rpmTRV = 0;
  rpmTAV = 0;

  attachInterrupt(0, flow_fun, RISING);
  flowHV= 0;
  flowTRV= 0;
  flowTAV= 0;

  Serial.begin(9600);
  
}

void loop(){
  if ((long)(millis()-millishv) >=0){
  Serial.print("rpmcount: "); 
  Serial.println(rpmHV);
  Serial.print("flowcount: ");
  Serial.println(flowHV);
  millishv=millis() + HVmillis;
  }}
  
  void rpm_fun()
{
  rpmHV++;
  rpmTRV++;
  rpmTAV++;

}

void flow_fun()
{
  flowHV++;
  flowTRV++;
  flowTAV++;
}

Edit, the problem also occurs when i disconnect the hall sensor from the arduino