[Accessibility] buttons inside modal stop working when Screen Reader and keyboard is using

[ElenaShevchenko]

Summary: Accessibility issue with focus

Steps to reproduce:

1. Open demo provided is demo section https://codepen.io/claydiffrient/pen/KNxgav
2. Switch on Scree Reader (NVDA + Chrome+ Windows in my case)
3. Use keyboard and push "Enter" on "trigger Modal" button -> Modal is visible
4. Push "Tab" to chose "Close Modal" button
5. Click "Enter" -> Nothing happens, modal is not closed

Additional notes:

In case user will use mouse instead keyboard everything will work.
In case Screen Reader will be switched on when modal is already opened everything will be ok

Looks like modal lost focus some how.