new tmux pane not sourcing zshrc file

Using iTerm2 with tmux and zsh. I have an issue that new tmux panes doesn't source ~/.zshrc file I have customized my terminal (when running source ~/.zshrc manually it works) but when opening new pane (C+b and c) it doesn't source the file ~/.tmux.conf

set -g default-terminal "screen-256color"
set -g default-command /bin/zsh
set-option -g default-shell /bin/zsh

~/.zshrc

export ZSH="$HOME/.oh-my-zsh"

plugins=(git tmux)

ZSH_TMUX_AUTOSTART=true

source $ZSH/oh-my-zsh.sh

 if [[ -n $SSH_CONNECTION ]]; then
   export EDITOR='vim'
 else
   export EDITOR='mvim'
 fi

export TERM=xterm-256color

eval "$(starship init zsh)"

iTerm settings [![iTerm settings] current terminal (on new pane) wanted terminal (on new pane)