How to to updata episodes number?

I am making code by reinforcement learning.

The purpose of reinforcement learning describes a simple pendulum that throws a ball at a target point.

However, the figure below shows the learning situation.

I feel that there is a problem with the episode reward.

Is this because the episodes haven't been updated, that is, the observations haven't been updated?

Or is there some other cause?

Below is the code for the update of the observed values.

 function [Observation,Reward,IsDone,LoggedSignals] = step(this,Action)
            
            LoggedSignals = [];
            
            Force = getForce(this,Action);　　　　　　　　　　　% torque
            
            theta = this.State(1);                             % state is pendulum's theta (angular)
            w = this.State(2);                                 % w is Angular velocity of the pendulum
            
       
            IsDone = false;
            
            R = 0;
            
            
            % pendulum dynamics Euler method
            
           
            q2 =  w - (this.g/this.L) *theta*this.Ts- this.b * this.Ts-Force*this.Ts; % angular velocity
            q1 = theta + w * this.Ts;                                                 % angular 
            
            % ball dynamics
            ball_x = this.L * sin(q1);          % x initial position of ball 
            ball_y = -this.L * cos(q1);         % y initial position of ball
            ball_time = sqrt(2*abs(ball_y)/9.8);      % reaching time of ball
            ball_reach = ball_x +abs(q2).*ball_time;  % Horizontal ball flight distance
          
            ball_gosa = ball_reach-this.Target;　　　　% Difference between target point and flight distance　　　
            q3 = ball_gosa;　　　　　　　　　
            
            
            % condition of reward
            % If the difference between the target point and the flight distance is 1 or less, a reward will be given.
            if  0 < q3 && q3 < 1
                IsDone = true;
                R = this.RewardForStrike;
            else
                R = this.RewardForNotFalling;
            end
           
            
            Observation = [q1 q2 q3 Force]';               % observation states
            
            this.State = Observation;
            
            this.IsDone = IsDone;
            
            Reward = getReward(this,R);
            
            notifyEnvUpdated(this);
            
        end