Problem with character limit in word count plugin

Please advise. I have a problem with character limit in word count plugin. When I reached the limit, I tried to continue typing and got this bug. See my attached image.

I'm using word count plugin for ckeditor 4.4.0. Here is my settings in config.js:

CKEDITOR.editorConfig = function( config ) {
    // Define changes to default configuration here. For example:
    // config.language = 'fr';
    // config.uiColor = '#AADC6E';
    config.toolbarGroups = [
        { name: 'basicstyles', groups: [ 'basicstyles' ] },
        { name: 'paragraph', groups: [ 'list', 'indent', 'align' ] },
        { name: 'styles' },
        { name: 'colors' }
    ];

    config.extraPlugins = 'wordcount';
    
    config.wordcount = {
    
        // Whether or not you want to show the Word Count
        showWordCount: false,
    
        // Whether or not you want to show the Char Count
        showCharCount: true,
    
        // Whether or not to include Html chars in the Char Count
        countHTML: false,
        
        charLimit: 10
    };
};