System object not stop on breakpoints in stepImpl block when running simulink

I have several breakpoints in the system object files.

The debugger does not stop on the breakpoints in the "stepImpl" part. But they do stop in the parts such as "getOutputDataTypeImpl" or "getOutputSizeImpl" and so on.

I used the "system object-->simulink extension" file and modified it a little bit.

classdef test0_systemObject < matlab.System & matlab.system.mixin.Propagates ...
        & matlab.system.mixin.CustomIcon
    % Untitled Add summary here
    %
    % NOTE: When renaming the class name Untitled, the file name
    % and constructor name must be updated to use the class name.
    %
    % This template includes most, but not all, possible properties, attributes,
    % and methods that you can implement for a System object in Simulink.

    % Public, tunable properties
    properties
        
    end

    % Public, non-tunable properties
    properties(Nontunable)

    end

    properties(DiscreteState)

    end

    % Pre-computed constants
    properties(Access = private)
        output=5;
    end

    methods
        % Constructor
        function obj = test0_systemObject(varargin)
            % Support name-value pair arguments when constructing object
            setProperties(obj,nargin,varargin{:})
        end
    end

    methods(Access = protected)
        %% Common functions
        function setupImpl(obj)
            % Perform one-time calculations, such as computing constants
        end

        function [y1,y2] = stepImpl(obj,u)
            % Implement algorithm. Calculate y as a function of input u and
            % discrete states.
            obj.output = obj.output+u;
            y1 = u;
            y2 = obj.output;
        end

        function resetImpl(obj)
            % Initialize / reset discrete-state properties
        end

        %% Backup/restore functions
%         function s = saveObjectImpl(obj)
%             % Set properties in structure s to values in object obj
% 
%             % Set public properties and states
%             s = [e-mail](obj);
% 
%             % Set private and protected properties
%             %s.myproperty = obj.myproperty;
%         end
% 
%         function loadObjectImpl(obj,s,wasLocked)
%             % Set properties in object obj to values in structure s
% 
%             % Set private and protected properties
%             % obj.myproperty = s.myproperty; 
% 
%             % Set public properties and states
%             [e-mail](obj,s,wasLocked);
%         end

        %% Simulink functions
%         function ds = getDiscreteStateImpl(obj)
%             % Return structure of properties with DiscreteState attribute
%             ds = struct([]);
%         end

        function flag = isInputSizeMutableImpl(obj,index)
            % Return false if input size cannot change
            % between calls to the System object
            flag = false;
        end

        function [y1,y2] = getOutputSizeImpl(obj)
            % Return size for each output port
            y1 = [1 1];
            y2 = [1 1];

            % Example: inherit size from first input port
            % out = propagatedInputSize(obj,1);
        end
        
        function [y1,y2] = isOutputFixedSizeImpl(obj)
            % Return true for each output port with fixed size
            y1      = true;
            y2 = true;        
        end
        
        function [y1,y2]= getOutputDataTypeImpl(obj)
            % Return data type for each output port
            y1      = "double";
            y2 = "double";
        end
        
        function [y1,y2] = isOutputComplexImpl(obj)
            % Return true for each output port with complex data
            y1      = false;
            y2 = false;    
        end

    end


end

[shu]

For anyone who may come aross the same problem, refer to the link:

MATLAB System Block - MATLAB & Simulink (mathworks.com)

Change the system object from "code generation" to "Interpreted execution", the "stepImpl" part can be debugged now.