UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/57.0.2987.133 Safari/537.36

Example URL:
http://www.pnas.org/content/113/46/12946.abstract

Steps to reproduce the problem:
1. Go to the webpage
2. Look at the missing menu between the Authors and the Significance sections. The menu contains PDF button. 

What is the expected behavior?
The menu exists in Firefox, Explorer. 

What went wrong?
The menu is not there. 

Does it occur on multiple sites: N/A

Is it a problem with a plugin? N/A 

Did this work before? N/A 

Does this work in other browsers? Yes

Chrome version: 57.0.2987.133  Channel: stable
OS Version: arch 4.10.8
Flash Version: Shockwave Flash 25.0 r0

*I've tried Chrome on Windows and the menu with the PDF and that did not work. Despite the explorer working fine. 
*I've checked if there is any significant different in the code sent to Firefox and Chromium, but could not see the culprit: https://www.diffchecker.com/efyIFTD9
*I've changed my Chromium setting to identify as explorer, firefox on windows and on mac. This brought no change.