HC 12 with Servo

I m a little bit confused . I am making an rc plane and I need to control an 120 degree servo with two buttons
When button1 is being pressed the motor should go to 120
When button2 is being pressed the motor should go to 0
And when no button isbeing pressed the motor should stay on 60 ° but instead it goes full right no matter what button I press . Is there an issue with the arduino servo library and the HC12 and what can I do about it ?
Reciever :

#include <SoftwareSerial.h>
#include <Servo.h>
int ROT ;
Servo myservo;
SoftwareSerial HC12(10, 11); 
void setup() {
  Serial.begin(9600);            
  HC12.begin(9600); 
  myservo.attach(9);
  myservo.write(60);
}
void loop() {
          
   while ( HC12.available() ) {       
   ROT = HC12.read();
   }
  Serial.println(ROT);
  if ( ROT == 1){
    myservo.write(0);
  }
  else if ( ROT == 2 ){
    myservo.write(120);
  }
  else {
    myservo.write(60);
  }
}

Transmitter :

#include <SoftwareSerial.h>
int LEFT ; 
int RIGHT; 
int ROT = 0 ;
SoftwareSerial HC12(10, 11); 
void setup() {
  Serial.begin(9600);             
  HC12.begin(9600);               
  
}
void loop() {
LEFT = digitalRead(A0);
RIGHT = digitalRead(A1);
if (RIGHT == HIGH ){
  ROT = 2;
}

else if ( LEFT == HIGH ){
  ROT = 1;
}

else {
ROT = 0 ;
}
HC12.write(ROT);
  }

SoftwareSerial Will mess up the timing for your servo (higher priority interrupt and super slow at 9600 bauds to get a byte)

Since you don’t print anything use your hardware serial port for your HC12 (will need to unplug while uploading)

You could also get a Mega, for the extra hardware serial ports - that will make your life easier

If you want to stick to what you have Try switching to AltSoftSerial and ServoTimer2 (you will need to use pulse rather than degrees )