Improve the Accessibility in Microsoft Word add in

The Microsoft Word add-in I built has this activity:

It provided a button to select a Content Control inside the Word document, and user will do editing inside the content control.
After finished the editing, the expected behavior is the user should be able to use the keyboard to focus back to my Word add-in.
Now it's un-able to navigate back to the add-in using keyboard.
The Github issue link: https://github.com/OfficeDev/office-js/issues/4549