rhythmbox on Ubuntu 18.04 does not adopt CSD even when default alternative toolbar plugin is ON

[Beaver Fever]

Description: Ubuntu 18.04 LTS
Release: 18.04

rhythmbox:
  Installed: 3.4.2-4ubuntu1
  Candidate: 3.4.2-4ubuntu1
  Version table:
 *** 3.4.2-4ubuntu1 500
        500 http://de.archive.ubuntu.com/ubuntu bionic/main amd64 Packages
        100 /var/lib/dpkg/status

I expect to see GNOME CSD in Rhythmbox, but today I saw that CSD was not being implemented and the old giant titlebar was implemented. Not sure when this change took place, but I noticed it today. I checked the plugins and Alternative Toolbar plugin was turned ON. I'd not touched plugin settings at all since installation. I was using stock Rhythmbox - never touched settings.

[Beaver Fever (beaverfever)]

Sorry, I noticed there is another bug filed:
https://bugs.launchpad.net/ubuntu/+source/rhythmbox/+bug/1720649

This is exactly the situation in my case as well. I'm not sure how to delete this bug report.

[Beaver Fever (beaverfever)]

But, then again, I can't get CSD to work even after switching Application menu back ON in the top bar.