Dev Close Browser Delay

[tomscharbach]

I've been noticing an odd anomaly with the Dev build over the last couple weeks. 

When I click the "X" to close the browser, I experience a roughly 2 second delay before the browser closes.  Every once in a while, the delay goes longer and I have to click the "X" again to get the browser to close.  I am not experiencing this with the Stable build.  The Stable build closes instantaneously.

The anomaly has existed for about three weeks.  When I first noticed it on the 82.0.446.0 (March 11 release) build, I ignored it, assuming that a new build would resolve the issue.  The issue persisted with the 82.0.453.2 (March 19 release), and continues with the recent updated version (Version 83.0.461.1 (Official build) dev (64-bit).

The anomaly manifests on each of the three computers on which Dev is installed (all run Win10 Pro 18363.752, but ran a slightly earlier version before last week's optional update). 

I am not experiencing this with the Stable build (Version 80.0.361.69 (Official build) (64-bit)) on the computers, so the anomaly seems to be tied to recent Dev releases. 

My setup on Stable and Dev builds is identical, generally "stock" with no extensions of add-ons.  I do change a few defaults, but the changes are the same on both Stable and Dev builds.  All builds sync settings through my Microsoft account.

I've reported this to Feedback, obviously, but I'm curious about whether anyone else has noticed a delay in browser close with either Dev or Canary builds recently.

[#2]

Does it happen when you are on a specific website or happens even when there is only NTP open?

[#3]

@HotCakeX "Does it happen when you are on a specific website or happens even when there is only NTP open?"

It doesn't seem to make any difference what tabs are open or closed. 

I have replicated the difference in response between Stable and Dev with the two browsers operating the same computer, with identical tabs opened.   

Because I sync startup on all instances of Edge Chromium tied to my MSA, both Stable and Dev on all my computers start with two Bing tabs opened; the anomaly occurs even when only those two tabs are open and nothing else is open or has been opened. 

That did spur a thought, though.  I almost always have a Bing tab or two open when I close the browser, and it occurred to me that Bing could be interacting with Dev to create the problem.  I tested this by opening an instance of Dev and an instance of Stable on a computer, replacing both Bing instances in each case with other websites.  I repeated the test 10 times using a variety of websites as substitutes for Bing, the opened tabs always identical between Stable and Dev on close.  I saw no change in behavior no matter what I did.  So I don't think that Bing is the culprit.

I've also tested with a single tab (the NTP tab) open on Stable and Dev.   That does not seem to make a difference.

The only constant seems to be that Stable (as does Firefox) closes instantly when I click the "X", and Dev lags 2-3 seconds in most cases, sometimes several seconds longer.  It is very odd, and I can't account for it.