There is an inconsistency in the numbering of virtual desktops between the Switch Window popup (built from plasma-workspace/containmentactions/switchwindow and configured by Configure Desktop - Mouse Actions and setting a button to activate the "Switch Window" popup) and the taskbar item RMB popup. As seen in the attached screen shots, the Switch Window popup numbers the desktops starting from 0 while the taskbar popup numbers them starting from 1. Since starting from 1 is the most natural choice to be presented to the user, I've assumed that the bug lies in the Switch Window popup and that it should number starting from 1 also.
Created attachment 121719 [details] Screen shot - Switch Window popup
Created attachment 121720 [details] Screen shot - Taskbar popup
This is with the Switch Window action configuration set to "Display all windows in one list".
https://phabricator.kde.org/D22740
Git commit eed2d620cbd55a74c8621f38ce224eda80731cc1 by Jonathan Marten. Committed on 17/09/2019 at 06:25. Pushed by marten into branch 'master'. Consistent virtual desktop numbering between Switch Window popup and taskbar The Switch Window popup menu originally numbered the desktops starting from 0, in contrast to the KWin and Task Manager menus which start from 1. Adjust the Switch Window numbering to start from 1 also. Do not use the internal desktop ID for this, on X11 it is indeed the 1-based desktop number but on Wayland it is a UUID string. Differential Revision: https://phabricator.kde.org/D22740 M +2 -2 containmentactions/switchwindow/switch.cpp https://commits.kde.org/plasma-workspace/eed2d620cbd55a74c8621f38ce224eda80731cc1