PreserveAspectRatio:none for svg embeds

Hi there,
I´ve got an embed with svg image code in it.
PreserveAspectRatio is set to none, to fit into the flex-layout. So the image should shrink and grow without an aspect ratio.
Unfortunately the expected behavior is not always working as you can see in this video. The image stops shrinking at a certain viewport height. But it should shrink constantly, so that the buttons are always visible.

Do you know what I´m missing?
The layout should always look like that:

Here is my site Read-Only: LINK
Page name: AspectRatio Issue

(how to share your site Read-Only link)