UserAgent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.87 Safari/537.36

Steps to reproduce the problem:
1. Enable chrome://flags/#enable-experimental-web-platform-features
2. Run this example http://jsbin.com/pebehefuye/edit?html,css,output
3. The left panel 1 doesn't render backdrop blur correctly. 
4. It seems that the backdrop filter works only if it's applied directly to the element, which has set css position to absolute (Panel 2 in example). But if is the backdrop filter applied to any of it's children (see panel 1), the filter is not rendered.

What is the expected behavior?
Both panels will apply the backdrop filter.

What went wrong?
If I set the backdrop filter to any children, not directly to the absolute positioned element then it doesn't render backdrop filter.

Did this work before? No 

Does this work in other browsers? Yes

Chrome version: 54.0.2840.87  Channel: stable
OS Version: 6.1 (Windows 7, Windows Server 2008 R2)
Flash Version: Shockwave Flash 23.0 r0

I tested it also in the Safari v9.1.2 running on OS X 10.11.6 and it runs correctly - both panels are rendered with blur over the Lorem ipsum text.