Window rules not working

[sladkkr]

Describe the bug
Maybe I'm making some obvious mistakes but window rules are not working in my Wayfire session.
Here are the snippets:

[core]
plugins = animate command foreign-toplevel invert oswitch place shortcuts-inhibit autostart xdg-activation fast-switcher focus-request preserve-output input-method-v1 window-rules vswitch

[window-rules]
telegram = on create if app_id is "org.telegram.desktop" then assign_workspace 0 1
spotify = on create if title is "Spotify Free" then assign_workspace 0 1
firefox = on create if app_id is "firefox" then assign_workspace 1 0
firefox_pip_on_top = on create if title is "Obraz w obrazie" then set always_on_top
firefox_pip_size = on create if title is "Obraz w obrazie" then resize 480 360
firefox_pip_position = on create if title is "Obraz w obrazie" then move 3360 1800
firefox_pip_unmaximize = on create if title is "Obraz w obrazie" then unmaximize

To Reproduce

1. Add window rules to a Wayfire configuration.
2. Start the application having declared window rules.

Expected behavior
Application respects window rules, like workspace_assign, resize and move.

Wayfire version
0.9.0 for Nixpkgs (using the NixOS Unstable)