I have noticed that the “Window Control Panel” for the Composer is not working completely correctly. If I close the Composer Window Control Panel, I cannot reopen it. This does not affect the composer bar or the composer panel.
As a workaround I go to the cursor settings under Beta and deactivate and activate “Window Control Panel” again.
I saw the video whilst it was up, it was a good reproduction of the issue.
Hopefully one of the devs will see the issue shortly and it will be added to their ‘to-fix’ list.
To summarise it, as you said in your original post, the ‘window control panel’ icon in composer is not working completely correctly when opening and closing composer, the ‘click handler’ for the icon seems to become unresponsive.
Same problems. When you close the window pane and use other command such as ‘ctrl+i’, then you just cant use the 'ctrl+shift+i‘ to open the pane again.