Menuitems with actions cannot be set sensitive when in popup menus (using Glade/Python)

[Simon Lambourn]

The bug may be assigned to the wrong package: I'm using Glade 3.22.1 and Python 3.7.5.

Using popup menus, if I assign Gio.Actions to the menuitems, the menuitems become insensitive, so you cannot click on them, even if they have a handler for the "activate" signal as well.
I can assign Gio.Actions successfully to menuitems in a menubar, or a drop_down menu attached to a menubar, or to other clickable widgets such as buttons, so I think the logic works.

The Glade xml output looks as if it is correctly specified (although I'm no expert), so I guess that Gtk.Builder is not connecting the signals properly. Or there might be a restriction that I'm not aware of... so apologies if I am trying to do something not supported, but I have tried to research this.

Behaviour: menuitems in popup menus that have actions assigned are always insensitive and cannot be made sensitive.

Expected behaviour: menuitems in popup menus that have actions assigned should be sensitive and activatable.

I have attached the python and glade code which demonstrate the problem.

ProblemType: Bug
DistroRelease: Ubuntu 19.10
Package: libgtk-3-0 3.24.12-1ubuntu1
ProcVersionSignature: Ubuntu 5.3.0-29.31-generic 5.3.13
Uname: Linux 5.3.0-29-generic x86_64
ApportVersion: 2.20.11-0ubuntu8.2
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Sun Feb 16 20:37:22 2020
SourcePackage: gtk+3.0
UpgradeStatus: Upgraded to eoan on 2019-10-23 (115 days ago)

[Simon Lambourn (simon-lambourn-o)]

Glade file to go with the python file