Not getting zsh completion for `project:` in commands

When I try to do completion for the `project:` element in a command, nothing happens when I `` to try to complete a project name.

Example:
`task list project:Cli`

nothing happens despite having several project names that being with `Cli`

Other completions work perfectly fine.

i'm running 2.6.1 of TW and oh_my_zsh with the taskwarrior plugin. Not sure if this is a TW issue or oh_my_zsh.