UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.84 Safari/537.36

Steps to reproduce the problem:
1. Start Chrome with the --auto-open-devtools-for-tabs flag
2. Enable the setting "Disable cache (while DevTools is open)"
3. Load a page from a server that sends cache headers.
4. Make a change on the server that alters one of the cached files.
4. Duplicate the tab.

What is the expected behavior?
The change should be immediately picked up, as Chrome should not use cached resources in the new tab, as DevTools is open.

What went wrong?
The new tab loads cached resources, ignoring the DevTools setting.

Did this work before? N/A 

Chrome version: 63.0.3239.84  Channel: n/a
OS Version: OS X 10.13.2
Flash Version: