Flow Meter in GUI doesn't work

PaulS:
That method of counting pulses absolutely guarantees that you will miss pulses.

You have interrupts turned off most of the time. Yet, you expect to send and receive serial data with interrupts disabled. That is NOT going to happen.

count1 is incremented by the ISR, and used by loop(). Yet, it is not declared volatile, so loop() has no idea that the variable was updated by other code.

Leave interrupts on ALL the time, except for the VERY brief time you make a copy of count1 and reset it to 0.

So you are saying to do something like this in the main loop:

recvInfo();
  lightLED(); //Function for motors
  ultrasonicSensor(); //Geist sensor function
  ultrasonicSensor1(); //Quarry sensor function
  noInterrupts(); //Disable Interrupts
  count1 = 0; //count variable for flow meters
  
  interrupts(); //Enable Interrupts
  
  
  flowRate = (count1 * 2.25); //Take pulses and multiply by 2.25mL
  flowRate = flowRate * 60; //Convert seconds to minutes
  flowRate = flowRate / 1000; //Convert mL to Liters (L / Min)
  
  Serial.println(flowRate); //Print flowRate to Serial
  Serial.flush();
}//end loop