In plasmashell 5.27.5 on Debian GNU/Linux 12 (bookworm), I have several virtual desktops, and I use the ‘Special window/application setting’ option to make Thunderbird, Firefox etc start up on an individual, specific desktop and with a fixed position and size, which mostly works very well. The exception is a VirtualBox window, which simply ignores my choices.
Do any of you guys have an idea about how to make this work?