Browser window doesn't close after completing a pop up

Captchas

[X] I have read the instructions.
[X] I have searched existing issues and avoided creating duplicates.
[X] I am not filing an enhancement request.

What happened?

When logging with Google OAuth for example, after the pop up tab terminates it closes itself and browser goes on to open my essential tab after finishing it, instead of the new window closing itself.

That's mildly annoying since I have whatsapp open on my essential tab and that causes it to move the whatsapp session to another window instead of my main one.

Reproducible?

[X] I have checked that this issue cannot be reproduced on Mozilla Firefox.

Version

Mozilla Zen 1.0.1-a.19

What platform are you seeing the problem on?

Linux

Relevant log output

No response

zen-browser / desktop