Popup menus block system hotkeys on Linux
I'm trying to see if there is a solution or workaround for the following (perhaps rather strange) problem.
I'm trying to make a screenshot of ParaView's UI with one of the popup menus open (let's say, component selection for coloring), so that menu's contents are visible.
On my system, opening any of the popup menus blocks all system hotkeys (Alt+Tab, Win key, all F-keys... you name it), which happens to include the PrintScreen keyboard button. Switching focus to another window while keeping the menu open is seemingly impossible.
At the same time, there are definitely UI screenshots out there like the one I want (e.g. in https://blog.kitware.com/paraview-5-9-0-release-notes/), so I'm wondering if this is something specific to my system.
I'm running Ubuntu 20.04.2 with GNOME/X11 and ParaView 5.9.1.
Client Information: Version: 5.9.1 VTK Version: Qt Version: 5.12.9 vtkIdType size: 64bits Embedded Python: On Python Library Path: /opt/paraview-5.9.1/lib/python3.8 Python Library Version: 3.8.8 (default, May 17 2021, 15:58:51) [GCC 7.3.1 20180303 (Red Hat 7.3.1-5)] Python Numpy Support: On Python Numpy Path: /opt/paraview-5.9.1/lib/python3.8/site-packages/numpy Python Numpy Version: 1.19.2 Python Matplotlib Support: On Python Matplotlib Path: /opt/paraview-5.9.1/lib/python3.8/site-packages/matplotlib Python Matplotlib Version: 3.2.1 Python Testing: Off MPI Enabled: On Disable Registry: Off Test Directory: Data Directory: OpenGL Vendor: NVIDIA Corporation OpenGL Version: 3.2.0 NVIDIA 460.80 OpenGL Renderer: GeForce GTX 1050 Ti/PCIe/SSE2 Connection Information: Remote Connection: No