Drupal Multistep forms - focus

I have a drupal module that generates one or multiple multistep forms that can be placed on one page. Each form has one text area and 3 buttons. Each multistep form has an unique identifier and they behave independently one of another even if more than one multistep form is placed on the same page. Upon entering some text in the textarea of a form and upon hitting enter in that text area one the button Check is clicked using a javascript on the javascript. If the user entered the right text then the Check button disappears, the text area is disabled and another button appears: Next. This is done via a form submit. After this form submit the focus is lost, it's not set on any html object anymore. I need it that after this form submit when a user hits again enter the Next button should be triggered. It is important that the Next button of the right form is clicked and not another Next button of another multistep form that can be on the same page. Some of the calls are ajax based. The buttons can have unique identifiers. I have already given to the text area a unique identifier. You can change both the drupal module as well as a javascript. The solution must work on all mobile phones (android, iOS) as well as all browsers (Firefox, Chrome, IE, Edge, Safari) P.S. I'm also searching for somebody to give more projects/work in the future.