UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.181 Safari/537.36

Steps to reproduce the problem:
1.  Just add shadow to iframe, some external url seems ok, but internal seems to be have the issue.
2. Heres the url try in different browsers, seems to be an issue in opera too.
3. https://jsfiddle.net/ycpg2oe7/5/

What is the expected behavior?
To see the shadow like we did in older versions of chrome (i believe 65 or 64)

What went wrong?
The shadow in our app has been here for a long time on the iframe and then something changed in chrome and now the shadow is no longer visible.

Did this work before? Yes 65 or older I believe

Does this work in other browsers? Yes

Chrome version: 66.0.3359.181  Channel: stable
OS Version: OS X 10.12.6
Flash Version: 

Its a super strange bug, because if the high is changed it sometimes displays the shadow or sometimes when the body of inner html has margin it sometimes works, I did some test i did to try to resolve it myself with no real fix.
 

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	Screen Shot 2018-05-28 at 10.55.31.png 543 KB View Download