oh-my-zsh tmux plugin does not work when using antigen

[NellyWhads]

Description

When enabling the oh-my-zsh tmux plugin, tmux tab completion is broken (commands, flags, and session names).
This behaviour has been seen on the default versions of tmux and zsh available on Ubuntu 18.04 and Ubuntu 22.04 respectively.

Steps to reproduce

Minimal steps to reproduce this behavior.

1 - install tmux
2 - install zsh
3a - enable tmux plugin using traditional oh-my-zsh installation
(reset .zshrc file)
3b - enable tmux plugin using antigen bare minimum configuration for oh-my-zsh tmux plugin

Expected behavior:

- Tab completion works in both 3a and 3b

Observed behavior

• Tab completion works in 3a, but not in 3b

Software version

Matched in pairs as per the two tests

• antigen version: v2.2.2 and v2.2.2
• zsh --version: 5.8.1 and 5.4.2
• tmux -V: 3.2a and 2.6
• uname -a
  • Ubuntu 22.04: Linux [redacted] 5.15.0-58-generic #64-Ubuntu SMP Thu Jan 5 11:43:13 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux
  • Ubuntu 18.04: Linux [redacted] 4.15.0-106-generic #107-Ubuntu SMP Thu Jun 4 11:27:52 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

Configuration

.zshrc for vanilla oh-my-zsh test:
This template with the additional tmux plugin enabled here.

.zshrc for antigen test:

source [path_to_antigen.zsh]
antigen use oh-my-zsh
antigen bundle tmux
antigen apply