Hi Curtis,
I apologize, but I am working on another project at the moment, however, I tested using your own page as I noted above, so the issue would not be my js version ??
I do not expect the focus to leave the popup once the popup is displayed. A user should be able to hit OK, Cancel or Esc to exit. That is all. Tabbing through the menu and address bar only adds confusion, and is not compliant, from my understanding.
Check out this link (https://www.w3.org/TR/wai-aria-practices-1.1/examples/dialog-modal/dialog.html) and scroll to the light blue box with the heading Keyboard Support. This explains compliant behavior.
Hope that helps, Curtis! Thanks again for you work on this. It is appreciated and I admire your intelligence and determination to get this working ?? – scott