UserAgent: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.181 Safari/537.36

Steps to reproduce the problem:
1. Open in chrome two tabs.
2. In first tab run JS code confirm('Any message to confirm')
3. Go to the second tab and then back to the first tab and confirm dialog is away

What is the expected behavior?
Confirm dialog should be still there and wait for user decision. Repeat reproduced problem with "alert" dialog not "confirm" and there is no bug. Alert still waits for user.

What went wrong?
Confirm dialog disappear.

Did this work before? N/A 

Chrome version: 66.0.3359.181  Channel: stable
OS Version: 6.1 (Windows 7, Windows Server 2008 R2)
Flash Version: 

Confirm dialog must still wait for user. Maybe confirm message says something that user must check/verify that information using google/internet in another tab and when he goes back to origin tab to confirm dialog, it is unexpectedly away.