Describe the bug

When you are tabbing thru a modal (like accessibility users). After the focus goes from the last button to the whole modal. the page behind the modal get scrolled to bottom.

Steps to reproduce the bug

1. Go to https://bootstrap-vue.js.org/docs/components/modal/
2. Click on Launch demo modal
3. Tab thru the modal until you hit OK button
4. Tab one more time

Expected behavior

Page should not scrolled down in the background.

Versions

Environment:

• OS: Windows 10
• Browser: Chrome
• Version: 74

Additional context

This seems to be more an annoyance/weird behavior than a usability issue cause focus goes back to button that triggers the modal after closing it anyway