UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36

Steps to reproduce the problem:
1. Start chrome with command line arguments --proxy-server and set some proxy server which requires authentication.
2. Go to any website, chrome should ask you for a username and password. Enter username/password.
3. Go to https://ifconfig.co/ip and ensure that proxy is working
4. Call Network.clearBrowserCache command on Dev Tools Protocol
5. Go to any website, chrome does not asks you anymore for proxy credentials. I tried this even with my own implementation of proxy extension for chrome, and it does not work. I can give you my implementation of the extension if you want.

What is the expected behavior?
That after Network.clearBrowserCache is called by using DevTools Protocol, Chrome asks you again for username and password of a proxy.

What went wrong?
Chrome uses old username and password.

Did this work before? N/A 

Chrome version: 67.0.3396.99  Channel: stable
OS Version: 10.0
Flash Version: 

If you have any other idea how would I clear http auth cache by using Dev Tools Protocol it would be greatly appreciated.