Windows only move from one task bar to the other when the window is minimized

[John Waffle]

Setup:

- I have a setup with two monitors on Lubuntu 18.04 x86_64. Let's call them Monitor A and Monitor B.

- I have one panel docked to the bottom of the screen for both monitors, the only thing in the panel is a Task Bar (stretched)

- In the task bar options, I used these settings (same for both monitors):

"Show windows from all desktops": False
"Only show windows on the same monitor as the task bar": True

- If it matters, Monitor A is to the left of Monitor B
(xrandr --output <Monitor B> --right-of <Monitor A>)

Steps to reproduce:

1. Open a window on Monitor A
2. Drag that window to Monitor B

(Note that the button is not showing on the task bar for Monitor B)

3. Click the button for that window (still showing on Monitor A's task bar), it will minimize to Monitor B's task bar.

Additional notes:
- I was using a very similar setup on Lubuntu 16.04 and I didn't have this issue, I recently reformatted my hard disk and installed Lubuntu 18.04 (a fresh install, not an upgrade). I'm pretty sure that on Lubuntu 16.04 when I dragged a window from one monitor to another, it just appeared on the task bar immediately.

[John Waffle (jwaffe75)]

I think I might have posted this in the wrong place, sorry about that. Is there an LXDE launchpad?

[John Waffle (jwaffe75)]

After talking to wxl in irc.freenode.net\lubuntu, it seems like this is more related to openbox

[John Waffle (jwaffe75)]

wxl changed their mind, lxpanel it is

[Martin (m-a-r-t-i-n)]

I also have this issue with an identical setup.

Another thing I noticed is that when I move the window from monitor A to B, the button stays on A. When I move the window back from B to A, then the button suddenly appears on B (where the window isn't present anymore) but disappears from A (where the window is now).

[Chris Guiver (guiverc)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. Please execute the following command only once, as it will automatically gather debugging information, in a terminal:

apport-collect 1790973

When reporting bugs in the future please use apport by using 'ubuntu-bug' and the name of the package affected. You can learn more about this functionality at https://wiki.ubuntu.com/ReportingBugs.