When enabling a secondary monitor, which is located left of the primary, all windows are moved to the secondary monitor, this includes dockers liker Plank. No matter if you use the system settings, Meta+p or xrandr.
Thanks for the report. Window placement is the sole responsibility of KWin, so I'll reassign it to kwin.
Adding a screen changes the virtual layout. Windows are placed on positions in the virtual layout - e.g. at 0/0. By adding a screen left to the existing a new screen is put to the position 0/0. Unfortunately we cannot read the users mind and don't know whether the user expects windows to stay at 0/0 or to move to another screen.
No need to read the users mind. Just like in every other scenario the user would want his windows to stay on the Primary screen. If the coordinates of the primary screen change, window positions should be updated too. This is expected behavior. Resolved invalid? is that a bad joke or something?
*** This bug has been marked as a duplicate of bug 427875 ***
*** Bug 441169 has been marked as a duplicate of this bug. ***
*** Bug 418470 has been marked as a duplicate of this bug. ***
*** Bug 430005 has been marked as a duplicate of this bug. ***
*** Bug 431533 has been marked as a duplicate of this bug. ***
*** Bug 434970 has been marked as a duplicate of this bug. ***
*** Bug 439366 has been marked as a duplicate of this bug. ***
*** Bug 442953 has been marked as a duplicate of this bug. ***
Git commit 4928f4db5b810969c70d549729c23ff95d1a6781 by Vlad Zahorodnii. Committed on 30/10/2021 at 14:02. Pushed by vladz into branch 'master'. Try to preserve window position relative to their outputs during hotplug Currently, if an output is hotplugged, all windows will be scrambled, which is highly annoying. With this change, windows will stick to their outputs if an output has been connected or disconnected. Related: bug 296673, bug 412703, bug 443698 M +10 -12 src/abstract_client.cpp https://invent.kde.org/plasma/kwin/commit/4928f4db5b810969c70d549729c23ff95d1a6781
*** Bug 451057 has been marked as a duplicate of this bug. ***
Got another report of this issue (Bug 451057) from someone using Plasma 5.24.2; re-opening.
In Plasma 5.25 problem still exist. I have additional problem, because Plasma's windows moving. I could life with it, if Plasma's windows will restore one's position after screen disconnection.
In my case, I have a secondary monitor which I don't regularly power up unless I have a video to watch. All is well until the primary monitor goes to sleep or is powered off. When awoken, all my windows have moved over to the (not powered on) secondary monitor. Quite annoying to move them all back.
This should have been fixed by https://invent.kde.org/plasma/kwin/-/merge_requests/2573 in Plasma 5.26!
Does that commit also fix bug 356225?
No, I'm afraid KWin isn't responsible for Panel positioning--Plasma is. So a different fix will be needed.