`(command &)` from .zshrc not executed until shell closed

[rogier-stegeman]

Describe the bug

My .zshrc contains lines that call python scripts:

function f() {
  (command python /path/to/app.py > dev/null 2>&1 &)
}

(The bug also happens with something simple like (command notify-send foo &))

These run perfectly fine in Konsole and Kitty. But from Guake shells they are not executed until the shell is closed, or I open another tab. The rest of the .zshrc executes fine.

For example:

Every time a shell is opened, or a condition is met, command X should run. Instead:

1. Open fresh Guake
2. (X should run on start or when condition is met, but doesn't)
3. Open new tab in Guake
4. X runs
5. Close tab
6. Close last tab
7. X runs (too late)

Expected behavior

As soon as my lines are reached in .zshrc, or when they are trigged, for them to be executed.

Actual behavior

command not being executed until the shell is closed.

To Reproduce

Add (command notify-send foo &) to .zshrc

$ guake --support

Guake Version: 3.10 Vte Version: 0.74.0 Vte Runtime Version: 0.74.0 -------------------------------------------------- GTK+ Version: 3.24.38 GDK Backend: