## Reproduce the bug:

For example if I have:

- App 1
- App 2
- App 3
- App 4
  - App 4 – Win 1
  - App 4 – Win 2
- App 5

If I try to reorder the windows of app 4, I get this result:

- App 2
- App 1
- App 3
- App 4
  - App 4 – Win 2
  - App 4 – Win 1
- App 5

As if App 1 was linked to «App 4 – Win 1» and App 2 to «App 4 – Win 2».

The get the same result if I try to exchange App 1 and App 2 when the group popup is visible, except that it’s laggy, especially when reordering several times in a row.


## Excepted behavior

- When reordering windows inside a group popup, it should not exchange top-level windows.
- When reordering top-level windows when a group popup is visible, close the popup on drag start (the bug is not triggered when popup group is not visible, and closing a popup when doing something else is a more common behavior).


## Code investigation

The problem seems to lie around here[1]. As the function does the excepted change, I guess the side effect is a bug in the model, but I couldn’t find where the TasksModel or move function is defined.

[1]: <https://phabricator.kde.org/source/plasma-desktop/browse/master/applets/taskmanager/package/contents/ui/MouseHandler.qml;8af970fd49f3ca33450cf3ccd81856694a0dc752$111>