UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:59.0) Gecko/20100101 Firefox/59.0

Steps to reproduce the problem:
1. Open two incogitio windows
2. Open www.google.com in both
3. Zoom out in one of the browsers

What is the expected behavior?
Only one of the browsers changes zoom level

What went wrong?
Both browsers zoom level changes.

Did this work before? N/A 

Chrome version: 63.0.3239.132 (Official Build) (64-bit)  Channel: n/a
OS Version: OS X 10.13
Flash Version: 

Only happens if it's the same website open in both.