UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.87 Safari/537.36

Steps to reproduce the problem:
1. Build a site page containing a single image with source like "http://logdev.xiti.com/hit.xiti?s=410501" or "https://logs1225.xiti.com/hit.xiti?s=410501"
2. Clear all browsing data like cookies and cached images and files (or "clear site data" on application tab in DevTools).
3. Visit the page with Chrome with DevTools opened on Network tab.
4. Check network trafic with another proxy/tool like Fiddler or Charles.

What is the expected behavior?
Two requests should be generated:
- One making a redirection 302 (adding a third party cookie named "idxvr").
- Another one with status code 200.
This is what we get in Network tab.

What went wrong?
Three requests are generated:
- One making a redirection 302 (adding a third party cookie called "idxvr").
- Two others with status code 200.
This is what we actually get in Charles/Fiddler and in server logs.

Did this work before? No 

Chrome version: 67.0.3396.87  Channel: stable
OS Version: OS X 10.13.5
Flash Version: 

This problem occurs only when Network tab is opened and after redirection. If you try after closing/changing this tab, you'll only have two requests as expected.
We can reproduce it on : 
- different OS like macOS High Sierra or Windows10,
- different Chrome versions,
- on HTTP or HTTPS website

Could you explain this behavior?

Thx