Windows moving when monitor is (dis)connected
I have a somewhat similar issue than in issue #1046. I think it's the same cause but I could be wrong. I'm on archlinux, using Gnome 3.32.2 on wayland.
My setup is a laptop, and 2 external monitors connected through a DisplayLink dock. Most of the time, I don't use the laptop monitor. Whether I use it or not, my main monitor is always the first of the 2 external ones, so there is no workspaces moving from a monitor to another. The others are secondary monitors. I also use a fixed number of workspaces.
When I open or close my laptop with multiple windows opened on my 2 external monitors, some windows are moving from a monitor to the other, some aren't. As I can recall, only windows from my main monitor are moved to the secondary, not the other way around. It happens with both wayland native and xwayland applications.
See the Evolution window moving to the integrated monitor when I open the laptop: