Div with class "joyride-backdrop backdrop-bottom" isn't scaling up to full height in Safari

[tantebootsy]

Describe the bug
In Safari 14.1 the div with the class "joyride-backdrop backdrop-bottom" is only shown / scaling up to full height, after resizing the browser window a bit.

To Reproduce
Steps to reproduce the behavior:

1. Open Safari 14.1
2. go to https://tnicola.github.io/ngx-joyride/home
3. Start Tour
4. You will see the last overlay missing

Expected behavior
Div scales up fully.

Screenshots

Additional context
Problem can be fixed by replacing "height: 100%" with "flex-grow:1" for the div mentioned. Tested in Chrome, Firefox, MS Edge, Opera

[taiebnoe]

Same issue.