Semantic-Ui modal jittery behaviour-open source projects Semantic-Org/Semantic-UI

I am using Semantic-UI for designing a site for my project and I while using modal, I am seeing a jittery behaviour.

Here is the link : Click Here to Enter The Project Site

Press the ‘Register’ button to open up the modal dialog, and you will notice the dialog being formed in the left side and then shows up properly.

Cannot understand the reason for this behaviour.

Some help will be appreciated.

Code :

    
        
            
                Welcome to MeetUp!
            
            
Sign-up for a new account here.


        
        
            
                
                    
                        First Name
                        
                    
                    
                        Last Name
                        
                    
                
            

            
                
                    Email
                    
                
                
                    Gender
                    
                        Select
                        
                        
                        
                            
                                
                                Male
                            
                            
                                
                                Female
                            
                        
                    
                
            
            
                
                    Password
                    
                
                
                    Confirm Password
                    
                
            
            Register