[Bug]: Fullscreen + changing desktop breaks tiling

[andaag]

Summary

If I combine fullscreen windows + switching activities the windows gets into a weird state.

I ... do this a lot and I've been confused as hell as to why I sometimes loose windows on top/on bottom of others 😂

Steps to Reproduce

1. Start 2 windows
2. Make one of them fullscreen in kde
3. Change to another desktop
4. Change back again
5. Turn off fullscreen on that window
6. The fullscreen window will return to its previous tile position, but the other window won't know its there and will be filling the entire window under the fullscreened window.

Expected behavior

That the tiling works as expected

Screenshots

https://user-images.githubusercontent.com/826023/186865125-eb36cf68-cf08-4878-9ddf-9d2f17b3ad2b.mp4

Bismuth version

3.1.2-1 (deb, ubuntu repo)

KDE Plasma version

5.24.4

The platform KWin is running on

X11

Additional context

No response

[andaag]

I think this also breaks if you get a notification while a window is fullscreened... which might explain why I feel like I randomly bump into this a lot.