Can't set a checkbox to checked in tinyMCE editor

Question

Working on a project where we insert HTML inside a tinyMCE editor. I have a requirement to be able to check/uncheck the required checkbox control. If I place a break point on the editor click event it catches in the debugger and as you can see the checkbox is checked.But as soon as the event finished running the state of the checkbox goes back to unchecked.I have tried manually setting the value to checked inside the event.I have also tried stopping event propagation by using:

 e.preventDefault();
 e.stopPropagation();

But nothing seems to work and the checkbox always goes back to unchecked.Any tips from tinyMCE experts welcome