Form submit button not clickable sometime when rendered using Block

Scenario:

I have created login form using webform and placed on home page as block for anonymous users. So sometime login form's submit button is not clickable.

Debugging:

After debugging code i have observed that , removeAttr in webform.form.submit_once.js file is not always removing attribute like webform-submitted , but this is strangely inconsistent. It doesn't work sometimes. Because of this I m not able to submit form , because of this line "if($form.attr('webform-submitted')) {return false; }".

Solution:

After changing line "$form.removeAttr('webform-submitted');" to "$form.attr('webform-submitted', '');" it is working perfectly fine.