Pretty much what the title says. Task manager shows all windows from all desktops and activities completely ignoring settings that forbid it.
This issue is already known and mentioned in the Errata: https://community.kde.org/Plasma/5.9_Errata#Wayland
*** Bug 397490 has been marked as a duplicate of this bug. ***
I cannot reproduce this for virtual desktops – it only shows windows from the current desktop for me, unless I change the setting to no limit it to the current desktop. Open window activities are still broken though! However, it may not be fault of the window switcher since it's not possible to assign a window to an activity at all when right-clicking its task bar entry. Also pinning application launch icons to only specific activities *does* work.
Yeah, the original issue described here is fixed now.