Motion control from analog input

Good afternoon. If I use arduino nano and use outputs 9-10-11 to control the motor. Does the frequency of all counters increase, or only those that work with these three outputs? I want to use input A6 to externally control the motor by applying a constant voltage in the range from 0.23 to 3.07 volts. More precisely, 0.23 is a full back. 3.07 full speed ahead. 1.16 stand still. My problem is that when the voltage is 1.16 the motor jerks. I have stretched the voltage limits when the motor should stand from 1.1 to 1.25 volts. He began to twitch less, but still continues. Further stretching leads to a large dead zone. Maybe someone knows how I can fix my problem?

#include <SimpleFOC.h>
// software interrupt library
#include <PciManager.h>
#include <PciListenerImp.h>
int S;
BLDCMotor motor = BLDCMotor(15);
BLDCDriver3PWM driver = BLDCDriver3PWM(9, 10, 11, 8);
Encoder encoder = Encoder(2, 3, 600 , A5);
void doA(){encoder.handleA();}
void doB(){encoder.handleB();}
void doIndex(){encoder.handleIndex();}
PciListenerImp listenerIndex(encoder.index_pin, doIndex);
float target_velocity = 0;
Commander command = Commander(Serial);
void doTarget(char* cmd) { command.scalar(&target_velocity, cmd); }

void setup() {
encoder.init();
encoder.enableInterrupts(doA, doB);  
PciManager.registerListener(&listenerIndex);
motor.linkSensor(&encoder);
driver.voltage_power_supply = 24;
driver.init();
motor.linkDriver(&driver);
motor.voltage_sensor_align = 3;
motor.velocity_index_search = 3;
motor.controller = MotionControlType::velocity;
motor.PID_velocity.P = 0.2f;
motor.PID_velocity.I = 0;
motor.PID_velocity.D = 0;
motor.voltage_limit = 8;
motor.PID_velocity.output_ramp = 1000;
motor.LPF_velocity.Tf = 0.01f;
motor.P_angle.P = 50;
motor.velocity_limit = 50;
motor.init();
motor.initFOC();}
float almost_zero_velocity = 5; // rad/s
void loop() {
  S=map(analogRead(6), 339, 618, 0, -42);
  if(motor.shaft_velocity > almost_zero_velocity){motor.zero_electric_angle = 0.63;}
  else if(motor.shaft_velocity < -almost_zero_velocity){motor.zero_electric_angle =1.82 ;}
  else{ motor.zero_electric_angle = 1.22;}
  motor.loopFOC();
 motor.move(S);
 command.run();
}

this is an example of my code